I've only built 1 boat and it wasn't a B & B design, it was a Bolger Junebug. The plan calls for planks of closed cell foam in the bow and stern for floatation. Instead, I built air chambers in the bow and stern. Each chamber has a screw in deck plate that I can remove for ventilation and inspection. I would do this again, I think it's a bit lighter and I can use the chambers for small item storage. The design calls for a fixed rudder and I changed to a kick up design. I would definitely do this again. The design had a clip on leeboard that broke the first time it touched bottom. I changed to a Jim Michalak style pivoting leeboard and I'm much happier with it.