- Thu May 28, 2009 1:25 pm
Ah--the shape of the boat at the bow is cosmetic AND has a real effect on performance.
First thing is that you want the boat to have pleasing lines. That means different things to different people. That's why most boats have the rearward slope on the part of the bow above the waterline. That rearward slope can also come into play when cutting through waves and adding volume to the front so the boat won't submarine--but I believe that is overblown by most people.
From a strictly performance view I'd keep the part above the waterline square and only shape the part from the waterline down--but that's ugly, so we are compromising here.
How do we shape the part below the waterline? Once again--from a performance view--it could be square and pointed with no slope. BUT that could make it hard to handle--probably would if the stern is higher than the bow and you have current, wind, waves, or other factors. You also wouldn't be able to turn the boat (I take that back. It WOULD turn, but not when you want it to. It could probably swap ends on a dime if the bow got heavier than the stern and water built up on one side of the bow. Racers use this to good effect by having a seat that slides forward so they can whip around the buoy.) I built one like that. I ran into the bank. So we slope, add rocker, and and/or cut away the part at the bow (and the stern) to make the boat easier to handle and turn. Another factor, which is especially important in marathon boats and other boats that will see some hard use, is that the slope allows us to ramp, or ride up and over logs, rocks, paddlers that have fallen out of their boat, alligators, crazed cows--stuff like that. I mentioned crazed cows because I have had one jump off a 6' bluff, catch my boat, and try to hook me with its horns--all while it was in water over it's head. I didn't know cows could swim so good....
What you see on most of my S&G with the 2 step slope on the bow is an attempt to get all the length I can and still keep the look of the boat pleasing. Race boats are ugly.
In boat design simple questions have complicated answers....