I didn't build a GA but only built a Tolman Widebody 23 and a Jumbo 27. That part of the book and plans annoyed me to no end and there didn't seem to be any really good reason to make a collision chamber both above and below the chine. so I just put a vertical bulkhead and put the top glued right down onto the chine and it was super easy and strong too. Then I poked a drain hole in the middle of the bulkhead at the lowest point which we keep closed with a simple cork, pulling it out once in a while to check for water.
Well ... here's the end, if you want to bugged right up to it
It works like this .... first, you decide the correct height for a seat. Then because you want to sit on your bunk with a reading light while you have a couple of shots of Yukon, you design your bunks to be at the correct seating height. Then, because you want a queen-sized bed in the bow, you decide you want to utilize the space underneath the anchor well as part of the bed platform ... and since the bunk tops are also part of the bed platform, you make the top of the collision chamber the same height as the bunk tops. On some boats, this will be all above, party above and below, or even only below the chines. The chines, as noted above, are not part of the thinking and design process.
The bigger question is why have a collision chamber way up in the bow in the first place? Collisions are farm more likely along the on-plane waterline ... from deadheads, wiers, and the like ... and this is 1/3rd of the way back from the bow, where a collision chamber would only get in the way. The bunks and collision chamber are useful for only slow-speed damage ... dropping down onto a spiky rock as you are moving slowly and rising/dropping with the waves. I'd say mostly, that the collision chamber provides more structural advantages than safety advantages. Nice to have a horizontal and vertical bulkhead in the bow to stiffen up those forward bottom and side panels.
The end.
Brian
