Sunday, January 31, 2016

Boating observations

It has been a couple of years now that I've been pedaling the V15-6m, gathering data on a couple of different drive systems, stabilizing methods and construction techniques. Boiling it down to a few things results in the following observations:
  1. It is possible to build a stabilized monohull that high speed cruises about as fast as a Cadence without flying amas, at least for distances of up to 14 miles and waves of less than 2 feet. For me, this speed is about 6.25 to 6.5 mph.
  2. A stabilized monohull - at least one with a flexible shaft drive - is incapable of sprint speeds as fast as a Cadence. At no time could I push the V15-6m faster than 8.5 mph on flat, still water. I could push a Cadence to at least 10.5 mph on more than one occasion in identical conditions, and in one situation where, unfortunately, my GPS was not started I believe I got the boat on a plane at even higher speeds.
  3. A boat with adequate stabilizers is a good thing to be in when one wants to be relatively stress-free in big water conditions.
  4. Having a low center of gravity can do wonders for reducing the size of stabilizers needed.
  5. Having a fairly stiff and secure mounting mechanism for stabilizers helps to promote stability in big water conditions.
  6. Drop-down dagger stern rudders are far superior to dipping rudders for steering effectiveness and lower windage.
  7. Push buttons and ball pins are both good methods of securing nested composite tubes together.
  8. A propeller that is positioned near the middle of the hull rather than at the stern does not ventilate in most wave conditions.
  9. Twin bladed folding propellers are pretty good, but in conjunction with a flexible propeller shaft there is a tendency at most speeds lower than high cruising speed for the shaft to oscillate and potentially slam against the hull. 3-bladed fixed Cadence propellers work just as well for propulsion and are far smoother at all speeds.
  10. Twin bladed folding propellers tend to shed weeds better than fixed bladed propellers. Speaking of weeds, most weeds seem to collect on the V15-6m propeller strut rather than on the propeller or propeller shaft. On a Cadence, most weeds collect on the propeller shaft. A weed cutter helps a lot, but you are never sure if all the weeds are gone.
  11. A drop-down strut with a cable angle limiter, Delrin shaft bearing and ball propeller thrust bearing works quite well. Less energy is lost to shaft flex at higher energy output.
  12. A simple spring (or rubber band) mechanism to lock the strut in the up or down position works quite well for transportation, launching and beaching to keep the propeller out of the way.
  13. 1/8 inch non-stretching marine rated cord works well for steering control as well as for raising and lowering the rudder.
  14. #35 go-kart sprockets and chain are an excellent and relatively inexpensive source for the major parts of the drive mechanism where one is likely to make changes before settling on what works for them. Choose an adequately large chainring, and one can then fine tune by switching out the smaller sprocket. Otherwise, these components are overkill and will likely never wear out nor break.
  15. The use of industrial pillow block bearings for the crank is overkill, too, in terms of weight and frictional losses at the seals. However, they do make it a bit easier to adjust chain tension.
  16. 5/16" stainless spring steel propeller shafts work very well.
  17. Mitrpak gear boxes are reliable and work well. The larger gear boxes have a bit more friction due to the seals, but this can be alleviated somewhat by breaking them in with an electric drill.
  18. A sharp edged bow cuts the water well, but a fairly significant bow wave is still created. Weeds and other floating debris can also be caught, causing drag.
  19. When surfing, it is possible for the bow to become submerged in a wave. If the deck is fairly flat, then the wave can travel all the way into the cockpit. Having a peaked deck prevents this, though if the bow does not have a lot of volume (as in the V15-6m), the bow can bury itself quite deeply into the wave before finally rising out. This slows the boat down considerably.
  20. Hand holds in the cockpit are very important. They give you something to hold onto when the boat pitches and rolls.
  21. Having a place to stow water bottles, food, clothing, etc., that are accessible while under way and are secure in the event of a capsize is good to have.
  22. Having a place to stow a canoe or kayak paddle that is easily accessible from the cockpit is very important, particularly when launching, beaching or fending off other boats. The method used to stow the paddle needs to be secure enough so the paddle can be washed away, yet easy enough for one to access it without difficulty.
  23. Having a boat that is under the 22 foot limit of the Washington State Ferry System reduces the cost of water transportation by a third. Having the height of the boat (plus car and roof rack) below 7' 6" reduces the cost even further.
  24. Using a dolly to launch a boat works, though it can be cumbersome. If the boat was light enough to carry, then that would be a great improvement. One would not have to worry about where to put the dolly or its safety while out on the water.
  25. 4mm marine grade Okoume plywood is very pretty, and very tough when used in a clamp-and-glue or stitch-and-glue construction. It is also generally fairly heavy.
  26. 6 ounce glass and foam is difficult to make pretty, is not as tough, but is generally quite a bit lighter than plywood.
  27. Pedal boats with gearboxes are noisy. It is difficult to hear what other boaters are saying if you are pedaling.
  28. If the outriggers are properly mounted in is possible to launch and board the boat from a low dock rather than have to wade into the water. This is easier with a Cadence than the V15-6m, as one can actually install and remove the outriggers while seated in the boat.
  29. It is important to have a way to pedal the boat without requiring special shoes to protect one's feet.
  30. Having a comfortable seat and seat back is critical. If you can't be comfortable while pedaling, or encounter pressure points from the PFD or seat cushion, then your time on the water will not be as enjoyable as it could be.