Thursday, July 17, 2014

Journey Across The Pamlico




The Pamlico Sound is the largest lagoon on the US east coast.  When Italian explorer Giovanni da Varrazzano reached the Pamlico Sound in 1524 he thought he was in the Pacific Ocean.  His report caused many errors in the naming of places on the map of North America.  Its vast size and numerous shoals present many dangers and rough ocean conditions.  For 2 years Lee endeavored to lead a kayak trip to cross the Pamlico Sound.  Such a trip would carry with it dangers inherent in an major open water crossing.  A paddler would have no place to bail out, rest, perform repairs, and have no shelter from storms and high winds.  The trip would also require a reliable weather window and excellent navigation practices.   In 2013 the time for the long anticipated trip came, but risky weather forced Lee to cancel the trip entirely.   He scheduled a second attempt the following year on July 12th, 2014 to leave from a public boating ramp at Stumpy Point on the mainland and cross the Pamlico Sound to the town of Rodanthe on North Carolina’s Outer Banks and return in the next 2 days when the weather permitted.  We estimated the crossing would be around 18 miles each direction with each crossing lasting a duration of 4.5 - 6 hours.  Our destination was Rodanthe Water Sports campground on the sound front and accessible directly by our kayaks.   To bolster our navigational tools, Lee studied surrounding landmarks that would be visible far out at sea.  He noted our destination was next to a water tank and near a radio tower.  He estimated the towers would be visible once we were 5 miles from shore on a relatively clear day.  Lee also picked out landmarks at our departure site to aid navigation home.  A water tank and a cell antenna a mile inland were the only distinguishing landmarks that could be seen 
at a distance for the return trip.  In preparation, I created two routes and downloaded them into my GPS a few nights before departure.  Lee had briefly contemplated leaving for Rodanthe from the port town of Engelhard which would  ve been an open crossing of 28 miles instead of the 18 miles we had planned if we had a south-west wind pushing us the entire way.  However, the winds that day were to be 10-15 mph from the north-east .  So we decided to depart from the originally planned site at Stumpy Point and deal with the wind and waves on our left beam.


Our departure point from the mainland was a wildlife
 ramp on a swampy rural hook shaped peninsula named Stumpy Point.  There were no stores or lodging facilities for 20 miles, so we staged our trip from the near by town of Engelhard which was dealing with a cleanup after hurricane Arthur passed by a a week earlier.  Mosquitos were everywhere, so the marina we had planned to camp at seemed even less inviting.  Soon after we arrived in Englelhard, we learned Chris would be meeting us at Stumpy Point for the departure.  On a whim, Lee and I decided to abandon our campsite plans and stay at the Hotel Engelhard overnight where we enjoyed good company and a hearty hot breakfast the next morning.    We started our day at 6:00 am and left for Stumpy Point after our hearty breakfast for a planned 8:00 am launch.  Driving the lonely road to the launch site we left civilization behind and contemplated the trip ahead as we stared into long empty road across a flat treeless landscape.  Chris was at the boat ramp as we arrived to begin the careful packing process of loading our kayaks for the trip.  Everything we needed along the way had to be easily accessible from the cockpit of a pitching kayak since we would not stop or get out of our kayaks until we landed in the Outer Banks.  All my food was in small plastic containers so I could grab them quickly from my day hatch.  I rigged 2 hydration systems with tubes inches from my mouth.  A 3 liter bladder strapped behind the cockpit, and a secondary 1.5 liter bladder inside my PFD.  I 
was not to use the water in my PFD until the 3 liter hydration unit was empty since it was my emergency water supply in case I was separated from my kayak and lost. I had both a VHF radio with an emergency location system and a SARSAT Personal Location Beacon.  I also carried 4 flares and a signal mirror in the front compartment of my PFD.  Attached to the side was my trusty whistle.  As we packed the NE wind penetrated the trees to remind us that this was not to be a calm day.  I worked hard all winter perfecting a bomb proof roll recovery at the pool and practiced often in the lake and during trips to ensure a good chance of recovery in the event of a capsize. 



We departed for our crossing at 8:45 am under the
morning sun through the tranquil waters inside the hook of Stumpy Point heading toward the point.   When we reached the point, the wind and waves were waiting for us as our kayaks slammed by the 1 ft chop on the left beam.  Once around the point, we set course to the town of Rodanthe on the Outer Banks far over an empty horizon.  The water flew over our kayaks, accented in gold by the morning sun.  For the entire trip each way I had my GPS route pointer displayed page.  Once my kayak was on course, I immediately took a compass bering to our destination in case my GPS should fail and checked it periodically along the way.  For the trip over we held to bering 120 degrees.  I found the compass was easier to steer my kayak by as the GPS screen was slow to correct 
 at times to the pitching kayak which made the route pointer seem to point erratically.   The waves and wind made their presence known as waves crashed into the port side of our kayaks and spilled over the deck.  My normally less stable kayak was a little bit more stable with the kayak loaded with gear and fresh water.  Despite the waves and wind hitting us, we were making way at a good 4.2-4.7 mph as our bows pitched over the waves.  The morning sun reflection from the waves and flying spray was beautiful.  With the pitching, we had to remain vigilant about staying on course with no visible landmarks to guide us.  Lee stressed that we should err our path to the
north to counter the inevitable southward drift of our kayaks caused by the wind and waves on our left beam.   I adjusted my paddle cadence to match the period of the waves to ensure my paddle was in the proper bracing position at all times to prevent a sudden capsize.  Lee periodically looked back to determine how far out from shore he could see our return trip landmarks.   As we moved beyond the sight of land I became more comfortable relying on my navigation instruments. 





At 4.5 miles out we sited the tall water tank next to our destination which was our landmark from the outer Banks.  Our kayaks pointed strait at the landmark as it was first sighted  reassured me my navigation instruments were spot on.  From then on we were able to visually navigate as we were most comfortable doing even though we were still a long way from spotting land.  The wind was a little stronger and the waves steepened as we were far from any shore.  As the trip wore on, the miles seemed to tick off slower as our landmark so far away was in no hurry to move closer.  We could not stop, so everything we did had to be accomplished very quickly and deliberately.  Every time a hand was taken off the paddle left us vulnerable to being knocked over by one of the constant barrage of waves hitting our beam.  Through the entire trip we always gripped our paddles firmly by at least one hand.  This trip was only the second expedition for my Epic Kayak and the first in rough water.  I found accessing my food more challenging than anticipated.  So I had to curtail my meals until the seas subsided enough to safely reach for my food.  The resulting loss of calories would later catch up with me. 


As we drew closer, we could start seeing more land features.  Radio antennas appeared from obscurity, later houses, business, and other land features appeared and at long last land.  The NE wind hitting us from the side all day was coming directly from the Atlantic, so as we drew closer to the Outer Banks the shrinking fetch lessened the size of the waves.  We could feel ourselves getting closer to the Outer Banks.  The beautiful sand dunes from the national seashore painted the island with a sparkling stroke of gold.   We saw navigation markers to the Oregon Inlet pass by as we directly headed to our destination.  Having no been able to replace the energy I lost was starting to take its toll and my pace slowed considerably
as I began to struggle the last few miles.  As we neared the shore, our kayaks passed into shallow water and saw jet skis, standup boards and the puzzled looks of people at play wondering where these three kayaks appearing from the abyss came from.  We landed on a gentle beach exactly 4.5 hours after launch and traveled 17.3 miles.  The staff on hand was kind enough to help us carry our loaded kayaks from the water’s edge to a grassy spot at the top of the bluff.  After nearly 5 hours we arrived and were starving hungry after a non stop trip.  We wasted no time unloading and pitching our tents so we could clean up and find some much needed food.   We walked next door to Lisa’s Pizza in Rodanthe where
 the 3 of us ate 2 large pizzas.  After which, we sat and savored the air conditioning for a while before leaving to find Chris some ice-cream.  We hit a few shops, then walked a mile north to see “Serendipity” where the movie “Nights in Rodanthe” was filmed.  The house had been moved from its romantic spot at the ocean’s edge to a safer lot inland.  We made our way to the beach and took in the sights of the beautifully quaint Rodanthe beach for a while and made our way back to the campground in time to watch a most beautiful sunset over the Pamlico Sound.  Before going to bed, we made preparations for a very early departure back the next morning.  This would be our only weather window since the
weather was forecast to deteriorate after noon.  For my part, I hoped and prayed for a calmer less rocky trip home.  After plugging in the route back on my GPS I started getting ready for bed.  We had a most exhilarating and satisfying day and slept well that night. 





The following morning, we departed Rodanthe at 7:15 am in crystal calm conditions.  The golden light of the sun cast a warm glow as we departed familiar surroundings into what appeared to be the imaginary realm of a dream where the sky  water were indistinguishable and objects real and imaginary appeared before us.  Waves at a distance refracted off the horizon and appeared as land before vanishing.  Clouds reflected off the water looked like a continuous sky above and below.  The silence was peaceful, but its emptiness lent it to a most surreal environment we passed into.  There were also the familiar sights of pelicans plunging after fish.  Once again we started with no landmarks and relied entirely on our navigation instruments.  I took my compass bering for the trip back across the sound .  We followed herring 300 back as we plugged forward through the dream like landscape.  We spotted many unexplained objects and anomalies.  What looked like a big block of pilings or a barge ahead of us was likely trees far over the horizon magnified by the air at the water’s surface.  As we paddled on, the tranquil conditions continued.  Unlike the trip over, we could actually converse in a normal voice as we found ourselves truly alone miles from anywhere. or anything.  We spotted a red marker on the same bering as our destination so we used it as a visual landmark knowing it was stationary, but not really knowing what it was until we were almost upon it.  It turned out to be a channel marker to the Oregon Inlet.  Once we passed it we once again navigated by our instruments until at 12.7 miles into the trip, we spotted our Stumpy Point landmark on the correct compass bering and backed up by my GPS route pointer. But It was very far away and we were a long way from spotting real land.  When visibility improved, we saw the lonely Bodie Island lighthouse to the north at a distance.  We were able to make our way back 
faster with the calm conditions and afforded more freedoms
to leisurly grab for food, drinks, lotion without worry of a capsize in rough waters.  But there was little to no wind to cool
us.  At one point Lee left his kayak and took a quick swim. I



considered rolling my kayak, but did not want to get my camera wet. 


After more miles ticked off, we could see tree covered
 land and soon after, a 5 mph South East wind kicked up.  As drew closer to our landmark, I noticed my GPS route pointer starting to diverge.  We were heading for what appeared to be the point just left of our landmark, but my route pointer was continuing to diverge.  I soon realized we made the error to use our landmark as a spot on marker for our destination when in reality,  it was a mile or so from our destination.  We corrected our course to my route which I set to a waypoint at the tip of Stumpy Point.  Finally, the end was near and the wind was picking up as though the Pamlico was not willing to let us go without a fight.   But soon we rounded the point and entered the protected waters inside the point and leisurely paddled the calm last quarter mile to the ramp and the end of our trip, arriving back at 11:35 am.  Very shortly after our return our weather window closed as we observed torrent water from where we came with numerous whitecaps. 


Over the two days of this trip each one of us had paddled the farthest we had ever done without stopping or setting foot on land. We had traveled 35 miles according to my GPS at an average of 3.7 mph.   I had learned much about navigation and the importance of researching landmarks in preparation.  Preparation will make your trip much easier.  I also was reminded of the importance of replenishing the calories burned.  Toward the end of the trip over, I found myself running low on energy and struggling near the end.   Know your body and give it what it needs.  We had a great time on Rodanthe and enjoyed good food.  The passages we well planned went well with no evil surprises.  Our passage home was a surreal experience at times.  One I have never experienced before.  In summary, we were rewarded with a intimate perspective and experience that only a kayak can offer: to be one with every nuance of the sea with a front row seat to her vast emptiness, might and brilliance.     


Equipment:
Kayaks:  QCC Q700X,  Epic 18x,  P&H Bahiya

Tuesday, October 15, 2013

Yoga for Paddlers



Reason #21. Yoga Makes us Better Paddlers by: 
         •Increasing our flexibility/torso rotation
      •Increasing our balance 
      •Prevents injury and delays age related physical ailments so       we can paddle for years to come
      •Helps us to focus and relax (when is focus important?) Big    seas, interesting conditions, navigating whitewater, combat    roll
      •When we are focused and relax, we have better performance



Why Do I Practice Yoga? 
After years of endurance horse back riding injuries and a serious whiplash injury that permanently straightened my neck vertebrae, I had very limited neck rotation and chronic back/shoulder pain
YOGA keeps me paddling and has increased my flexibility to allow me to roll, never would I have been able to do that without it
Yoga greatly enhances my connection w/
         mind, body, spirit, boat, nature
         and the water

Yoga Makes You More Grateful

When and Where? 
In a studio
Every day
At home
Shore side before entering a boat
In the boat (KAY-YOGA)
After paddling
Whenever sore, stiff, hurting
In the early morning
At your desk
In the evening
With your family
By yourself
With strangers in a class
Outside is the BEST! J 

Chris fit at 53



I am grateful for kayaking



Yoga isn't Just for Women! 
From Men’s Fitness Magazine, professional athletes who practice yoga:
Shaquille O’Neal Basketball
LeBron James Basketball
Ray Lewis Football
Victor Crews Football
Mike Krzyzewski Basketball
New Zealand Rugby teams
Philadelphia Eagles
Evan Longoria Baseball
Kevin Garrett Basketball
Vernon Lewis Football
Kevin Love Basketball
Joe Taft 



Men, Proceed with a Small Note of Caution:
 NY Times
Yoga for men can be harmful IF:
They ignore aches and pains
Force themselves into poses that they are not ready for (being more muscular than women, they tend to do this)
Don’t jump into advanced poses too quickly
Women naturally have more flexibility, men have more muscle and less flexibility
Begin with a certified YOGA instructor, beginner classes



Where to Start? 
Your local studio: we have partnered with mind/body/fitness yoga in Greensboro at www.mindbodyfitnessyoga.com 
At home: 
www.shopgetoutdoors.com 

www.yogaventures.com

www.amazon.com 
www.greenlandorbust.org











Friday, June 28, 2013

Laying the Foundation for Paddling Stronger: Cardiovascular Training Part II


by Stephen Knight

In the previous entry we began laying the groundwork for improving paddling fitness by ranking the changes in breathing due increased effort.  These changes were listed on a 1 to 10 scale to produce the Rated Perceived Exertion (RPE) Table.  We then assigned Training Zones (TZ) to the RPE scale in the second table as an abbreviated way of describing our efforts in order to train consistently. A benefit of using the RPE-TZ Table is that there’s no instrumentation – you are the “on-board computer”.

That’s not to say a Heart Rate Monitor  (HRM) isn’t useful, but it only generates numbers if you don’t know what’s driving them. Beats per minute (BPM) become useful when they’re coupled with the physiologic responses to increased effort like those described in the RPE Table.  This correlation lets us  devise fairly accurate TZs based on BPM at levels of exertion up to RPE 8.  Beyond that level of effort it’s not possible to determine an accurate lactate threshold and maximum heart rate outside of controlled testing conditions. Each person’s heart rate and response to exertion will be unique due to age, conditioning, state of rest, and innate physiology. That kind of precision is a lot more in-depth than we need.  For now, the RPE-TZ table and a sports watch are all that are needed.


Before getting started with any performance training,  meet with your physician for an objective evaluation of your overall health to ensure there aren’t any underlying conditions you need to know about, especially as we get older.  Read http://www.surfski.info/getting-started/tips-training/item/1025-atrial-fibrillation-and-the-athlete.html.  Furthermore, you need to establish a baseline to measure improvements over time.  You can expect positive changes in your health with consistent training. 

Time to get started.  Let’s assume that you fall into one of two groups, the first being relatively untrained and paddle infrequently or at a low intensity.  If this is the case and your goal is to improve your aerobic endurance then you’ve got to spend more time paddling outside of your comfort zone.

According to the RPE –TZ table, that’s going to require paddling at RPE 3-4 / TZ 2, where your effort is hard enough to make conversation difficult or in mostly short, broken sentences.  These are the long, steady sessions lasting one to four hours with few if any rest stops.  Start with 30 minutes to one hour at this level of paddling at least two times a week; more often will bring faster improvements. Keep extending your paddling at the same intensity until you literally feel that you can paddle all day.  Be patient, it could take several weeks before it gets easier and the full benefits may not be apparent for a month or longer. Can’t get out on the water as often as you’d like? You can get much the same benefit from cycling, running or swimming at the same RPE.  Personally, I encourage running or jogging on trails because in addition to an aerobic workout (yes, it’s OK to walk the hills), the uneven terrain improves your sense of balance and awareness while in motion.

If you fall into the second group where the goal is to improve speed and long-distance endurance then the intensity has to increase. A lot. Training must continue to build aerobic conditioning as well as adapt paddle specific muscles to long periods of endurance. 

There are two thoughts on how to achieve this goal, the first being to paddle at RPE 5 or TZ 3 for long steady efforts lasting one or more hours. At this level of effort your breathing is heavy but limited conversation is still possible.  Rest periods, if any, are kept very short. For many paddlers this level of conditioning is good enough but it can come up short if you are challenged by weather, currents or a heavily loaded kayak.

The second approach is where the effort is harder but the rewards are greater. You can expect substantial changes in endurance and power. Extended intervals at RPE 6-7/TZ4 will push your muscles to a point where they are just below the point of having sufficient oxygen to perform efficiently. This is the sub-lactate threshold, and training at this level may take 6-12 weeks before you see the benefits, assuming you have good aerobic fitness to start with.

Here’s an interval workout that takes a little over an hour. Warm up thoroughly for 15-30 minutes emphasizing good forward stroke form, leaving the socializing and skills practice for later. The first interval is 12 minutes at RPE 6-7 /TZ4. Your breathing will quickly become very deep and hard - talking will not be something you want to do, but you still can. This is not a sprint or all out effort. Your goal is to be able to complete the entire 12 minutes in the training zone.  Recovery! Three minutes of easy paddling. Now go again at the same high intensity for 10 minutes and recover for 2.5 minutes. Repeat for 8 minutes and recover for 2 minutes.  See a pattern? Now go for 6 minutes and recover for 1.5 minutes.  Last one, go for 4 minutes and cool down. You’re done for this session.  Interval workouts like this can be done two to three times a week as long as you allow 1-2 days of recovery time between sessions.

If at anytime you feel faint, or your breathing doesn’t seem to slow down when you let up, then stop.  You’re not ready for this level of workout.  Drop back to the RPE 5/TZ 3 workouts for several weeks before trying the higher intensity workout again. 

 “I don’t know. All of this sounds too much like race training”.  Well, you’re right. It is race training. However, your body doesn’t know the difference between competing in a race and paddling in challenging conditions. Skip even the least amount of conditioning and eventually fatigue leads to being left behind or you risk developing an injury. Those are reasons enough to incorporate some “race training” into your paddling.


Thanks for reading my blog entry for the Carolina Kayak Club.  I’ve been engaged in a number of outdoor activities for most all of my life as a participant and instructor. When not competing in trail running, bicycle and kayak races, I’m a USA Canoe and Kayak Team Paracanoe Coach and work with the Bridge-II-Sports Foundation for Adaptive Sports as the Parakayak Racing Club coach.

Friday, May 10, 2013

Know Your Kayak Under the Water (part 2): Stability Applications


There are many considerations between practicality, safety and desire when we shop for a kayak.  We may look for features that empower us for a realm of high adventure, or opt for a more modest craft to spend a few blissful hours in a tranquil paradise.  Whatever we choose should have features that reach a balance between our aspirations, skills and confidence on the water.  Unfortunately, there is no high tech miracle that will deliver all these things for every paddler.  But instead a game of give and take that forces us to sacrifice coveted qualities we desire for the performance we want.  Hull design is all about tradeoffs.  But kayak designers are using some innovative techniques to seemingly cheat the laws of physics.   In part 1 of this series, we examined the merits of primary and secondary stability and learned the importance of selecting the proper measurement of each to cultivate our skills and piece of mind while considering the consequences of the trade-offs for our choices.  In this article we will examine some real kayaks and identify performance characteristics from their hull features and uncover some tricks designers are using to deliver performance while minimizing sacrificial tradeoffs.

The first kayak we will analyze is a popular recreation kayak targeting novice and casual paddlers with a bit more prowess to take them a bit beyond novice conditions: The Tsunami from Wilderness Systems is the choice of a wide range of paddlers from the very novice to intermediate and delivers a surprising performance when pressed.

A kayak that fills this role must feel comfortable and secure to paddlers whom have never paddled a kayak, and those engaged in a secondary activity like birding or fishing.  So a high degree of primary stability is required.  In exchange for this up-front stability, a substantial wetted surface must be deployed underwater to provide an adequate angle of support for a comfortable stable feel (see Fig A).   The downside to providing this comfortable stability is the substantial drag from the broader wetted hull surface in addition to instability in rough conditions from the primary stability attempting to right itself on the slope of waves.  But it is a designer's job to cheat the laws of physics anyway they can to reclaim performance.  And the designers at Wilderness Systems had a few tricks up their sleeves.

   As we saw in part 1, the theatre of battle between the forces of stability and instability plays out in the form of rotation about the longitudinal axis spaning the length of the kayak.  To remain stable, the kayak must apply righting forces in the form of an opposing torque to this axis to counter the rotational destabilizing forces much like a wrench applies torque on a bolt.  As we know, a longer wrench shaft will apply more torque on the axis.  Moving the righting force away from that axis will allow the hull's beam to be used as leverage to magnify the forces of the primary and secondary stability as illustrated in figure B.  But designers pay a high premium in wetted surface drag if they extend primary stability to the entire width of the hull.  Figure A illustrates a cross-section at the center of the hull's length where the always deployed primary stability support is consuming wetted surface (WS) area.  However, secondary stability is much less costly to the drag of the kayak as it resides undeployed at and above the waterline.  So the kayak's streamline qualities will benefit most from this leverage if secondary stability resides at the furthest distance from the center axis.  As we can see from the figures above, the designers at Wilderness Systems took a bite out of the primary stability area and lowered the secondary stability to quickly deploy when the kayak leans, taking over at the point where the center of gravity pushes the primary stability to the point of capitulation (see figure B).  We can also see the wetspace drag is reduced from this design as the wetted area is reduced.   The handoff to secondary stability will also lend more stability in waves as the destabilizing effects from primary stability are reduced.  But one drawback to locating the secondary stability this low to the water is a jump in the amount of wetted surface drag when a heavy payload makes the kayak sit lower in the water as secondary stability  sitting passively above the waterline is deployed prematurely to bolster buoyancy.
Task of lip changes to rear flotation

As noted above, righting leverage is greatest at the widest point of the kayak, which in the Tsunami is located at the mid point in the hull's length.  So all of the stabilizing magic must take place at the mid point in the length where the hull is widest.  The rest of the hull's length will play little to no part in the stability at all since the leverage possible away from the widest beam is minuscule.  Therefore the totality of the hull fore and aft of the middle is better utilized for other tasks like tracking, decreasing water drag, and providing lift above steep waves.  So the protruding lip that provides secondary stability at the widest point serves a very different purpose of providing buoyancy at he bow and stern to lift them over steep waves and prevent the ends from perling.   This lip  fore and aft also keeps water from splashing on the paddler as waves hit the kayak.  Also notice how the the designers reduced the wetted area fore and aft of the middle.  The designers also added a dome area atop the ends to increase the buoyancy of the ends to reduce the tendency of periling into the waves.  The pointed tops allow the ends to cut to the surface of the wave quickly if they perl without shoveling the water.  These robust design measures at the ends is needed to overcome the lack of rocker the designers sacrificed to put more of the hull's waterline length to work in the water.  As we see later, a rocker design is for waves beyond the targeted market for this kayak, so the designers properly passed on a rocker design.   But they saw the need to bolster the ends to provide a capacity for waves, and this is one of the surprise competencies of the Tsunami.

The Gemini from Valley is an entirely different kayak designed for paddlers with a more advanced skill set.  As such, the designers opted to create a hull at the other end of the tradeoff spectrum to provide more performance and less initial stability, delegating the task of stability to the paddler's skill set.   However, the laws of physics stood directly in the path of their objectives.  They wanted to design a kayak nimble enough to play in the surf and be competent for long distance expeditions.  However, these two objectives put the designers at opposite ends of some significant tradeoffs of the hull design.  A single solution was not possible as these two objectives are irreconcilable without severely diluting their desired specialized performance.  So the designers decided to start from a common base design and spin off two distinct kayaks: the Gemini SP for surf play and the Gemini ST for for sport touring.  For the benefit of our discussion, we will examine the design of both of these kayaks in broader detail to understand the choices the designers faced and the implications on the stability of both kayaks.

Gemini SP underside with peeked keel and sidecut
The Gemini SP by Valley is a surf zone play boat, designed to be nimble in the surf and turn effectively when put on edge.  It is not designed for a comfortable ride over long straight distances for hours on end.  It will smash through opposing waves and surf high atop their crest.  In a surf environment,  primary stability is not needed or desired as we know primary stability will erroneously attempt to right the kayak sideways on sloped surfaces, which is never a good thing.   However, secondary stability is much more desired since it carries a delayed reaction and deploys much deeper into the lean, so a wave will pass before secondary stability can attempt to right the kayak on a slope.  Secondary stability will also protect the paddler form a capsize while edging the kayak and leaning into a wave while side-surfing. Tracking is not as important as turning for a surf zone play boat since it must react quickly and need not hold a straight course for very long.  So the designers created a short 14' 10" (452 cm) kayak with a lot of rocker to turn when on edge and stay above the waves with an upward orientated bow and stern.  However, the tradeoff to this rocker design does not allow the load to be dispersed over the length of the hull, resulting in a hull that concentrates the load at the cockpit.  A necessary sacrifice for the the high degree of coveted rocker.   Normally, the laws of physics would be unkind to such a design as the sagging cockpit would plow the water causing significant drag.   But the designers at Valley were not ready to give up on the kayak's prowess on smoother water.  After all, the goal was to create two similar kayaks for different purposes with similar characteristics.  To make the Gemini SP snappy as well as nimble, they needed to streamline the wetted surface beneath the cockpit to reduce drag.  And the only way to do this was to add buoyancy at the keel with a steep peaked bottom to reduce wetted surface by boosting the kayak a little higher from the keel.   To further reduce the wetted surface area the designers gave it hard chines with a cut-out similar to what we saw in the Tsunami (visible in the picture below).  The picture below also shows a benefit in the substantial amount of secondary stability in reserve above the waterline.  The tradeoff for all this is a reduced primary stability which is not desired in a surf playboat, resulting in an initially unstable feeling kayak that novices would find unsettling, but a high performer for its playground in the surf.

Gemini SP rides high with its rocker and ample sec stability
With less wetted surface the Gemini SP shows surprising speed for this type of kayak.  I was surprised one day on the lake when a friend in his Gemini SP was able to keep up with my Epic 18x on a casual cruise on a calm lake.  Claims that Valley highly touts in their promotional material.  

As a touring kayak, the Gemini ST sports tourer is designed for covering distances over calmer waters and provide the paddler with a more comfortable experience on the water over a longer span of time.  It is the same length of its twin the SP.   A touring kayak must be more efficient and minimize drag.   Given its very different mission, the ST has much less rocker, letting it disperse its load over the length of the kayak so it rides higher with less wetted surface drag.  The tradeoff is a less nimble kayak that does not edge as well and tends to perl into steep oncoming waves.   Unlike its twin, the ST does not need hard chines or a high peeked keel.  For its mission, the designers have given it softer chines with a flatter, low peaked bottom for more primary stability, but not too much, but allows the paddler to take a break, fish, shoot pictures, or relax without the unstable feeling of its twin the SP.   But the designers at Valley similarly did not want to give up on the nimbleness of the ST.  Without the high peeked bottom and the large cut out of the side, the designers had the luxury to bring down the sides of the hull closer to the water for a faster, more responsive secondary stability with a small cut for efficiency.  These curved sides will also lend some nimbleness to this rocker-less design when edging by putting a curve on the water (see part 3 of this series).  But the lack of rocker leaves the ST more susceptible to perl into sharp waves.  Often, manufacturers will compensate by adding more buoyancy to the bow and stern as we see in the SP.  But unlike its twin, the designers  remained true to their objective and sacrificed the surf readiness flotation volume at the ends for reduced drag and the efficiency of a more streamlined design.

So despite the very diverse performance objectives of the Valley Gemini designers, they created two kayaks rather than one to tackle an impossible spectrum of kayak performance goals in a truly unique way.  The complexity of these solutions underscores the value of hull design knowledge so we are able to understand and make intelligent choices from the abundance of sophisticated technology available.  Practically, we can only test a few kayaks on the water in far from ideal conditions.  We have seen how designers make significant tradeoffs to obtain their performance objectives.  But the motive that drives many kayak designers is to create a kayak that will fetch broad appeal so the company can monetize a successful product.  For other designers, its a labor of love they hope to monetize.  But the desires of a paddler lends purpose to a kayak as a tool leveraged to seek a path to their bliss and dreams.  Ideally, the paddler will seek the the empowering technology they need, grow into its characteristics, and find confidence to carry on to the next level.  A tall task for products of broad appeal.  But as paddlers we have choices and the ability to obtain knowledge of the science that goes into these more specialized and capable craft.  As for any endeavor no matter the discipline, the right tool is needed for the task.

In part 3 we will examine elements of hull design related to tracking and edging then dive into the hydrodynamics of skegs and directional hull features.


Copyright 2013 Lyman Copps