Hey all you landlubbing better bottle users, I want you to go walk up to you better bottle full of 5 gallons of water, and push in the sides of it, wrap your arms around it and squeeze it really tight and watch it flex.
Then start rocking it back and forth while you sing "row row row your boat" and watch how the liquid starts to build up momentum inside the BB and feel how the bottle flexes while the fluid momentum takes over.
Then think about it being on a rocking boat in a strong sea, maybe with a bungy cord across the middle, or some other method of securing it.
Then read this thread http://www.homebrewtalk.com/f11/better-bottle-failure-things-learned-97078/
As much as I love the better bottle for my home use, we are not talking about homes here we are talking about boats, where boats rock and slam up and down in rough waves....And everything on the boat whether stowed or not, does the same. And any liquid inside is going to be building up it's own momentum in the container.
Here's what BB mentioned in their email when Jason wrote them about his problem.
Every once in a blue moon a carboy develops a crack on the bottom. Nearly
all the time, it is because the user was rolling the carboy on its bottom
edge while it was full. The creates a tremendous amount of flexing in the
If brew on board is going to be trying to stow his fermenter in any way to keep it from rolling/sliding around below or above deck, it's going to build up so much liquid momentum and plastic flexation that more than likely any pressure point where the strapping crosses the flat plastic is going to become a weak spot on the bottle and during a major bit of boat movement in the opposite direction, like up and down on a wave trough, if going to result in a decapitated better bottle and precious beer all over the place.
Heck with enough constant liquid motion any point on the bb could become a flexation/weakness point and crack....Especially if there happens to be a weakpoint in the plastic anyway.
Brewonboard, if you insist on having a spigot for ease of use, then I think your best bet would be either a coopers pressure barrel or even just your plain ole Ale Pail with spigot.
If you can't find ones with spigot then just buy a bottling bucket spigot and mount it yourself (You might even want to add a dip tube like I show in my bottling tips thread.) And between spigot uses (while it is fermenting) wrap the outside of the spigot in some sanitized plastic bags with rubberbands, to keep and nasties from contaminating it.
The buckets have plenty of necessary headspace for 5-6 gallon batches, and the plastic is a little more rugged and has less flexation than the better bottles. And of course it's air tight.
I know that the idea of modding something else is appealing, but now that you've played around and seen what doesn't work, you can go with what we know works......And in your unique situation, I think it would work much better than the betterbottle where a lot of rocking and motion and flexation is going to occur.
I wouldn't risk my beer on a boat with the better bottles, no matter how awesome I think they are. They are just not flex proof enough for the high motion situations.