scamlin

David: Your point that it's more complex than a simple lever is well taken. However, the "other lever" you reference has the same ratio and the exactly the same effects: the shorter the paddle, the more the leverage. It doesn't matter where the fulcrum is. The relative contribution of the three movements (two levers plus torso rotation) will indeed vary a lot by individual and stroke, but I suspect for most paddlers (who do not emulate a racing stroke much at all), the two levers will dominate. The effects of short paddle length on the effectiveness of torso rotation? More stiffness and thus power transfer in the connection from torso to blade (leverage again), particularly in the first crucial foot of blade travel when your arms are fully extended; more likely to be vertical earlier in the stroke and therefore better transfer of power; easier and quicker to exit the water at the hip and thus less power robbing stroke behind the body; quicker cadence; etc. One could elaborate propositions and speculate on the effects endlessly. For instance, I'd guess that: 1. a longer paddle would cause the blade to spend more time off perpendicular to the direction of the stroke. 2. the shaft on a longer paddle would be more likely to be horizontal and thus result in a sweep as the other Rick (Stoehrer) suggests. The biomechanics get complicated pretty quickly.... Scott

Ed: A few years back, Ken Fink, retired oceanographer and owner of Posiden Kayak in Maine wrote an article in Atlantic Coastal Kayaker on paddles. The bottom line is that shorter is better because you have better leverage (See explanation at bottom of this message). Those who feel they are going faster because they are "working harder" with a longer paddle are right only in the sense that it is less efficient for the same speed or distance. It's the same as a cyclist going up hill in 10th gear. Instead, racing cyclists use lower gears to maintain a higher tempo because it's more efficient over the short or long haul. For most motions, the human body has more power and endurance when it expends light effort more frequently than heavy effort less frequently. Maybe Andrew can explain the physiology behind this phenomenon. Ken conducted experiments with his students and repeatedly showed that people paddle faster with shorter paddles...and can keep it up longer. He had a hard time getting his short paddle back after swapping with a student's long paddle. How short is short? The practical limit is whether the blade can be comfortably submerged in the water and whether you can clear your deck without hitting it with the blade. Surprisingly, Ken says that most paddlers, large and small, should use a paddle about 215 cm long. Long arms don't require longer paddles since they can reach the water just fine with a short paddle; shorter on a short torso may need a bit of length to clear the deck. Someone with a long torso and shorter arms might need a 220 cm to reach the water. 210 cm is where many experienced paddlers end up because it is more efficient, but does require a more vertical stroke and more rotation. Proper paddle length has little to do with your height: it's more the relationship of your hands to the water when sitting in the boat. Long paddles are especially problematic for paddlers who don't feel especially strong or who struggle to keep up on trips. Those who prefer a more horizontal stroke (or need one due to shoulder injuries) may need to use a longer paddle, but it is not likely to be as efficient, other things being equal. Whether it's the stroke mechanics that's causing shoulder problems is hard to say in the abstract, but lack of torso rotation can certainly contribute to shoulder injuries. Proper rotation keeps the shoulder in a much safer place through the stroke. Anyway, it's harder to do an adequate torso rotation with a horizontal stroke, but that is another topic. The main reason to go above 220 cm is if you're in a wide kayak (Sit on Top or double) where the beam is over 28 inches and you have difficulty reaching the water with a shorter paddle. Unfortunately, many shops still recommend and sell 230 cm paddles as a standard length and 240 cm for tall people. Don't listen to them as I did many years ago. Anyone want to buy my 230 cm...oops, wrong conference. Scott Leverage Explanation: Ken Fink's core insight is that a paddle in your hands is basically a lever: your blade is the load (Point A), your on-side hand is the fulcrum (Point and the offside hand is the force (Point C). The ratio of the lengths (i.e. BC/AB) determines the relative leverage you have on the blade. Since the distance between your hands is usually fixed, the ratio is determined by the distance from the on-side hand to the blade...which in turn depends on the overall paddle length. The shorter the paddle, the more leverage on the blade; the longer the paddle, the less the leverage. You can also improve the leverage on the blade by widening your grip since it improves the ratio; it's a handy technique when you need to temporarily increase acceleration (e.g. in surf), but you can only widen your grip so much without messing up your body mechanics. Surf kayakers use much shorter paddles (190 cm or so) in part for the power to sprint through and onto waves.

Rick: While there are many outfitting and paddling things to try, there is a simple way to control windcocking (bow turns into the wind when paddling): trim the boat. If the boat is really windcocking, moving or adding a bit of weight to the rear hatch will help neutralize the effects of the wind, much like a skeg. You have to experiment a bit to figure how much weight to use, and it will vary with the strength of the wind. Start with just a few pounds and add more to the rear hatch. As Brian says, total weight (ballast) is not the issue; it is the balance (trim) between the front and back (fore and aft) of the boat. Scott

Joe: Just a little history, hopefully distant. The business forum was originally created because for a time debates about the club's policies and practices on the General Message board were a bit too hot, lengthy and repetitive for many members. Most simply did not not want to have to wade through opinions about the club to get to what they wanted: paddling stuff! That's why there is a business forum. Whether the lack of conversation there is a good thing or not is another question. Scott

The DWR coating is actually critical to the warmth of Hydroskin...and indeed any kayak clothing. The reason? Evaporative cooling. As water evaporates, it releases a relatively huge amoung of energy/heat. One purpose of DWR coatings is to keep the water off the surface (beading and rolling off) and particularly from soaking into the material. While Hydro is useful in mild weather, I've found it particularly susceptible to evaporative cooling: the nylon skin gets wet, provides an ideal wick for cooling and given the .5mm thickness of the middle neoprene layer, not much to keep the cooling outer layer from sucking heat from the inner layer...and you. I've been really wearing Hydroskin chilled in 60 degree weather (not water!) when there is any kind of wind. Same applies to GoreTex, only not as dramatic. Some old school paddlers will tell you that GoreTex is not as warm as coated nylon because when the GoreTex gets wet and the moisture evaporates, it allows more moisture to get pulled through the material, which encourages evaporation in the insulating layer and ultimtely on your skin. Non-breathable shells can feel like a sauna, but inhibit evaporative cooling. Bottom line: while we rightfully worry about heat loss during immersion in the water, we spend virtually all of our time above water. If you attend a cold water workshop, you'll hear that you lose heat at a 25 times greater rate in water than in air. But that is conductive heat transfer (i.e. happens through physical contact) which is much more efficient in liquids than air due to the density of the medium. Evaporative cooling goes one step further: the physics of phase transition (i.e. from liquid to gas) is a much more efficient way to lose heat, and it happens while above water. The human body survives on this principle: it's called sweat. It's also the same principle behind air conditioners. So, be mindful of wetted out materials and the resulting evaporative cooling. Most garmets lose their DWR after only two or three seasons. You can reapply DWR coatings to both neoprene and shells, including GoreTex. There are both sprays and wash-in products. Be sure to thoroughly clean the garmet before treating it: otherwise the stuff won't stick. Some also claim a warm iron will refresh the DWR coating, but I've not tried it. Or you can simply put on a paddle jacket if the Hydroskin is wet and the wind is blowing. My experience is that the Hydroskin material does not breath particularly well (or at all), so I'm puzzled by Kevin's comment that it is a wicking layer under shells. The nylon lining is certainly more comfortable than raw neoprene, but there is really nowhere for the moisture to go when you sweat. I believe neoprene material itself IS waterproof: it's closed cell foam, is it not?. The leakage is seams and openings as others have noted. I typically wear a lightweight capiline layer under my Hydroskin for comfort even though it somehwat compromises fit and therefore warmth (see Dee's comment). The advantage of wearing neoprene under drysuits or drytops, it would seem to me, is more that it will provide insulation even if the shell is compromised and water enters. Insulation normally worn under shells such as fleece is pretty ineffective once wet. Scott

Carl: I'll take a shot at pulling together a few of the previous comments and add some speculative thoughts to puzzle through the question: As Billy says, a low brace works anywhere in the face of the wave where you have water moving "up" relative to the boat/paddle. You don't need the blade to be on top of the wave. In fact, on many waves, the low brace tends to ride the boat to the top of the face. The dynamic is that you're retarding the slide down the face of the wave, so it moves under you and up you go. That was the theory the coaches who taught us: the top is a better place to be anyway. The stronger the wave, the faster you'll ride up, or so they said. Your two scenarios seem to be wrestling with how to physically execute a low brace when the beam is at or past vertical. If so, you're right that it's hard to get good form (elbows above the shaft) and leverage on the paddle if it's up around your collar bones. The higher the deck or and shorter the paddler, the bigger the problem. Hence the instinct to go for a high brace. So if we're going to use low braces, the question is whether the aggressive lean is really needed. Is it to 1) put more body weight on the paddle; 2) keep the body past vertical (into the wave) or 3) to avoid tripping the hull itself on the downside of the wave or the sand. In short, how how does a radically rotated hull help in big waves? More body weight? I think a low brace offers more opportunity to bear down on the paddle shaft, IF you can get it under you. If you can put the blade in the middle (or even the bottom) of the wave face, you can keep the hull down and still lean on a low brace. I suspect the exaggerated hull rotation is an instinctive attempt to get the body over the centerline towards the wave: cocking the hips puts the torso outboard from the centerline of kayak, which tends to throw the torso into the wave face. But I think it's also an instinct many of us learned from hard lessons: don't let the downwave edge of the boat trip. However, while a hull cocked way up past vertical won't trip, it presents the sharp edge of the upwave sheerline to the wave which would dig in hard. That edge may create its own problems: it seems to keep the boat anchored under the breaking wave. I'm suggesting we keep the hull a bit more neutral than edged. Yet another well-known coach observed me edging hard in a bongo surf and commented that if I wanted to let the wave go under me (the goal for most of us once sideways to the wave), I'd have to flatten the hull so it could ride up and over. Works like a charm for moderate breaking waves and a low brace helps. But I've not really experimented on the monsters. Of course the trick is not let the downside edge of the boat trip--more difficult as a flatter hull is closer to tripping. So if you're trying a flatter hull, you still have the problem of how to do a low brace with the offside shear line sticking up. I suggest its a problem only if you are trying to keep the paddle shaft horizontal. If we let the paddle shaft angle up to clear the shear line, it would theoretically end up perpendicular to the angle of the wave face and maximize lift for the boat. However, the more the paddle shaft is off horizontal, the less it would keep the paddler from pitching into the wave: it would feel like spearing the wave. I think the answer is that the water in the wave is moving up relative to the paddler, so even if the blade is pointing down 45 degrees to the horizon, it is getting a strong lift UP and will support a leaning paddler in a low brace. So in summary: lean the boat (don't edge) with a relatively neutral (flat) hull, keep the paddle shaft and your hands down by your hips (the strongest and safest position for your shoulders) and don't worry where that puts the blade. The wave will take care of it. That's the logic: I welcome comments how it would work. Or maybe we should just go out and try it. As postscript, if you want to turn through the wave rather than survive it, a high brace may be appropriate--or really more of a bow rudder. It works like this: you are parallel to a breaking wave (on a surf break or even steep wind waves), you plant a vertical high brace/bow rudder upwave at the bow next to the boat, which anchors the bow and lets the breaking wave knocks the stern down wave...and voila, you're turned out to sea. Fortunately, the bow rudder is to the front which is the safer quadrant for the shoulder, but you do need to be careful not to reach out to the bow but rather tuck the onside elbow in against the ribs. To get the effect, however, you need to raise the offside hand (hence making it a bow rudder rather than a high brace) in order to get the blade to provide lateral resistance rather than vertical support. Again, works like a charm on moderate breaking waves, but I've not been tempted to experiment when I'm about to get crushed. Does any of this make sense? Scott

I'd be happy to tell some tall tales as well. Tell us what you need. 'course a half dozen references from your old paddle club might be a bit suspicious.... Best, Scott

On the flood, there's a short tidal stream into the cove for play: peal outs, eddy turns, maybe rolls or rescues in current, etc. That's what Rick is looking for. Rest of the cove is scenic but not particularly exciting. Scott

Palm is a high end Brit paddle gear manufacturer. Good stuff. Unless it was on a deep sale, my guess was the Palm drysuit was not GoreTex. Kokotat itself sells a breathable, non-GoreTex suit for half the price of a comparable GoreTex suit (under $400 without booties). See http://www.nrsweb.com/shop/product.asp?pfid=2262&deptid=1174. The non-GoreTex don't breathe as well, but are more than adequate and a whole lot better than a wetsuit for cold weather paddling. Scott

While you're trying to decide whether to get a different boat, you might try trimming your current boat. If the boat is really windcocking, moving or adding a bit of weight to the rear hatch will balance the effects of the wind, much like a skeg. The difference is you don't compromize maneuverability. You have to experiment a bit to figure how much weight to use, and it will vary with the strength of the wind. As long as you don't get carried away, a stern-weighted boat will track and turn just fine. Conceptually, you are increasing the lateral drag in the water at the stern and increasing the surface area above the water at the bow, which combine to neutralize windcocking. Scott

Ben: Some of the Scotish coaches last week carried soft surfboard wax in their PFDs for holes where the hull is leaking but there is still a fabric more or less intact. They just smear the wax into the matrix and paddle away. Works on the difficult challenge of wet hulls that defeat most tapes. The stuff serves double duty for slippery paddle shafts after you apply sun block. Some, but not all, still carry Denzo in their repair kits in the hatches for really big holes. Scott

Ernie: Can't add much to Ed's comments. I paddle the Avocet which is Valley's 16' version of the same hull. The secondary is indeed creamy and continuous; the final stability, while not huge, is very predictable. I have paddled the Aquanaut and it is similar. You shouldn't capsize unexpectedly once you learn the boat. I would also echo Ed's judgment: since both boats are both so capable in all conditions, you should consider use and comfort. The Force 5 has less rocker and therefore is marginally faster and tracks better and needs more edge to turn. The Aquanaut has more rocker and therefore while fast, tracks a bit looser but turns easier. So are do you want to emphasize play or miles? As for comfort, with my size 10 shoes, I find the Avocet's deck is a bit low, so I have to splay my toes to the side more than I'd like. Result? I get knee pain after a couple of hours of hard paddling because my knee joint is not properly aligned. So which boat has more room to properly align you size 12 shoes? You won't really know until you've paddled a full day in each. Can't go too far wrong with either boat. Scott

Brian: Thanks for the technical input. So we shouldn't worry if there is standing water in the cockpit or hatch during boat storage? I did forgot to mention another related issue: sea water that cannot dry out will smell! There are lots of microbes and other cool stuff in sea water (much more than fresh water lakes and ponds I think) that can ferment and get stinky if left damp. Main problem areas: 1. Closed hatches. Leave the hatches covers off when the boat is stored so the hatch can dry out. I either put them in the hatch itself or in the cockpit so I don't forget them when I pack up. 2. Interior surfaces covered by foam where the water can get trapped behind the foam. Potential areas are glued in foam such as a seat or foam spacers used for bulkhead footrests. If the water is trapped, it can get funky. A solid glue perimeter or groves to allow drainage can help. I do rinse in fresh water after each paddle, as much for the scum, sand and seaweed as damage to fiberglass. I won't go into the larger potential for neoprene and nylon gear to stink if not dried. I've found that a fresh water rinse and drying after each paddle prevents almost all smell problems. The drying is more important than the rinse. Microbes love damp. Best, Scott

I was taught that the interior of glass boats will absorb water over time. I believe this is happens with fresh or salt water: it simply seeps into the glass/resin matrix. But I don't really know: does anybody have a technical explanation? Dried salt will attract moisture out of the atmosphere: it's why your hands feel sticky after being in salt water. Suz is right: a rinse in salt water is better than no rinse since the resulting concentration of salt from the one final rinse is less than the accumulation of many layers salt from repeated wetting. However, it's hard to imagine the resulting dampness being enough to significantly seep into the boat. But I'm open to being convinced. Scott

It's a tautline hitch: http://www.iland.net/~jbritton/tautlinehitch.htm Scott

Sticky NDK/KayakSport and Valley rubber hatch covers are much easier to seat and seal properly if they are regularly coated/soaked in 303 Protectant. The difference in flexibility is dramatic. It also protects them from UV rays and general degradation like drying, cracking, etc. Since the Tempest hatch covers are a bit different material, not sure if this will work on yours. Might be worth a try. Scott

Properly fitted wetsuits are warm and comfortable, except in hot weather. The basic principle is to dress for immersion, not the air temps. Most of us wear some kind of synthetic underlayer under the wetsuit for comfort as much as warmth. It can range from a non-thermal rash guard (thin, slippery nylon), through thin poly wicking layer, to thick fleece. Wetsuits with some kind of nylon lining can be worn without anything underneath. The basic principle of wetsuits is that cold water does seep inside the neoprene, but the body warms it up and the insulating value of the neoprene helps keep it warm. To make this work, you need a tight fitting wetsuit: if it gapes around the edges, the cold water flushes the warmed-up layer of water out and it defeats the insulating value of the neoprene. Wetsuits are particularly hard to fit correctly around the armholes (most kayakers use Farmer John/Jane suits to give mobility in the arms) and around the neck (especially at the back of the neck between the shoulder blades). You can argue the effects of fleece worn under the wetsuit either way: it slows down flushing by stopping up the gaps; or it doesn't allow the neoprene to seal properly and wicks cold water in under the neoprene. It is usually more comfortable. Personally, I have found that moderate layers of fleece have little negative effect, but I would not want to put on a really thick fluffy fleece under the wetsuit: maybe expedition/winter weight underwear or medium fleece. You want to keep the neoprene close to the body. Fleece over the wetsuit would have a lot of insulative value when dry (especially under a shell layer), but not a lot once wet. Note that a well-fitting paddle jacket or drytop over the wetsuit is an ideal complement to a wetsuit as it greatly limits cold water flushing. After a swim, wet neoprene does suffer from evaporative cooling: you may continue to cool off, perhaps dangerously, once you get back in the boat. The paddle jacket really helps limit this risk. Note that 3mm is the standard thickness for cold water wetsuits: more is too stiff and less is a bit lightweight when trying to extend the season. One rule of thumb is that you need a wetsuit for immersion under 60 degree water temps and a drysuit under 50 degrees. In the Boston area, that extends the wetsuit paddling season from May to November. See http://www.nodc.noaa.gov/dsdt/cwtg/natl.html for a water temp table for New England. This assumes that you are only in the water long enough for a rescue; if you have to bob around for hours waiting to be noticed by someone, you'll be hypothermic. Of course, your actual comfort and survivability depends on a lot of factors, including motion in the water, wind above water, fatigue, hydration, food, etc. If you swim in 50 degree water with a 3mm wetsuit and paddle jacket, you'll certainly be cold, but will almost certainly survive to recover and get home--something you cannot count on without a wetsuit. Once the water gets cold, you'll want a neoprene or rubber/fleece hood and neoprene gloves. The former will greatly help limit loss of body heat and the latter will allow your fingers to function enough to rescue yourself. Best Regards, Scott

Joe: On a minor point in your report on the Tempest: Your GPS can switch among MPH (statute miles), KTS (knots) and KM (kilometers). If you're cruising in a plastic Tempest at 4.5 MPH without trying hard, either you're Olympic caliber or you have your GPS set to statute miles. I suspect the latter. Speeds on the water (including boats, winds and currents) are generally quoted in nautical miles, i.e. knots. A nautical mile is about 1.15 statute miles, so you'd subtract 13% from MPH to get KTS. So 4 MPH is 3.5 KTS and 4.5 MPH is about 3.9 KTS. When I first got my GPS, I starting checking my speeds and felt like a champ. Then I discovered the GPS setting, switched to KTS and joined the ranks of mere mortals. For the origins and technical basis for Knots, see the following link: http://www.onlineconversion.com/forum/forum_1076731782.htm Best Regards, Scott

Brad: Not far from the bridge. While the mid-point is imprecise and varies with tidal height and where you are on the tidal cycle, it's about 1/2 to 1 mile south of the Plum Is. Turnpike bridge, roughly where Little Pine Island Creek enters the sound. Best, Scott

Brian: I picked up the Pentax Optio WR last summer and have been mostly happy with it. Mine is the 2005 vintage 5 Meg version. I saw the 2006 version at 6 MP and it is significantly bigger to accommodate the larger LCD viewer. I like mine better due to the size and less drain in the battery. (I don't care about viewing pix; I'll do that when I get home. All I need to do is frame the shot). The pluses are the size and the waterproof rating: no problems despite sitting in my PFD pocket and occasionally banging around outside on the tether. Better to very good pix. No protruding lens, even with 3X optical zoom, so it slides easily into a PFD pocket. Good battery life. So far, bomb proof. (I do expect the seals to give out some day). Did I mention how small it is? The negatives? I miss the viewfinder: in full sun the image is barely adequate to frame the picture; sometimes I have to take off my sunglasses to see. But I have gotten used to it. Other quibbles: slow shutter (half or more second delay between depressing the shutter and the actual exposure; plus a second or two to process the picture). Mind you, I have it set on full resolution, which adds to the exposure times. Also, the small size makes it a bit hard to hold, paricularly with one hand, as I often do on the water. The smooth exterior doesn't give lots to hold onto. But with practice, no big deal. For the technically minded, it is not able to record images in raw format so you cannot process on your PC if you have the fancy software. For most uses, however, the in-camera processing is more than adequate. If you are coming from a SLR world, you'll miss the range of lenses and especially the ability to use filters; I do. But it is an exellent point and shoot, and it is very handy to use on the water. I sprang for a couple of 1Gb SD cards and don't regret it for a minute. Be sure to get extra batteries. Scott

Bob's trip was posted as Level 3 which was, as Ed indicates, appropriate. The conditions Bob reports are at the upper end of the Level 3 guidelines for wind (15 KTS). The use of "+" and "-" is not official; it's just a way some use to indicate whether the trip is likely to be at the upper end or lower end of the guidelines. More generally, with so many factors in the trip level ratings, they are guidelines and should be considered the starting point for considering whether the trip is appropriate to you. Consider the possibilities of specific conditions before you decide to join a trip: don't just go by a number. Ask the trip leader before the trip and at the beach if you have questions. In NSPN, it is your responsibility to decide if you are comfortable with the conditions and the possibility they may change. Remember, there is no guarantee the trip conditions will turn out to be within the trip's ratings. Scott

Agree with Carl's suggestions. However, note that the crossing to Warren Island is definitely NOT for novices in any boat. That channel can get very rough, especially when the wind is against the strong current. It can be misleading since the trip over can be like a lake, but conditions can change in a hurry. (Not to mention possible fog or the boat taffic). Best, Scott

John: Good description of the basic varieties of energy disapation of a wave. What I was asking Nick, perhaps not clearly, was what kind of events he had in mind BEFORE the swell hit inshore areas where the typical paddler would observe or confront the wave. My curiousity was about the relative wave height: if a swell in open ocean hit a inshore reef, shallow beach or cliff (as you describe), would the height be that much more than the NOAA forecast because it was cresting, dumping or reflecting? For example, would an eight foot wave in open ocean become 10 or 12 or more feet in height for a kayaker to deal with? Nick seemed to suggest that it would not be as terrifying as the statistics would suggest because some or most of the energy would have been bled off (via friction as you explain) by near the shore topography. In other words, features of the shore would decrease the energy (and therefore height) BEFORE it hit the shore or reefs near the shore where the kayaker would have to deal with the waves. In princple that makes sense, but it seems to me that this would be a caprice of the particular shore: in some areas it would happen; in others where there were no offshore obstructions, you'd get the full impact of an 8' swell, enhanced as the swell stood up on reefs, beaches or cliffs. Scott

Keep it in your day hatch as a spare. I do. Scott

Hmmmm. Waves lose a great deal....of what? Height? If so, how? Length/period? How? Energy? How? In other words, does "feeling the bottom" (even when not rearing up or breaking) begin to sap the energy of a wave, thus reducing the height and/or energy when it finally breaks? Or is hitting other near-shore obstructions such as narrow channels, wraping around points, etc.? Nick, what did you have in mind? Scott