We have a 2001 35 motion xp with with 500 EFI's. engines are forward of the trandsom about 40 inches. The bulk heads are nearly nonexistent . The tunnel is flexing so bad that the hull is cracking in several places. We are planning to pull the motors this coming fall to add cross supports and bulkheads to the engine compartment.we put a gopro camera in the engine compartment and was shocked on how much the tunnel and hell was flexing. We would like to get some insight on where to add and what material to make the bulkheads and supports from! Please help. Thankyou.

any pics of it as it is now? before you map out scantlings it will be important to figure a few things out, build schedule, material, core material to name a few. its also very important not to over build in any one particular area but to improve the build as a whole.



do you know if the hull is cored and if so what? just wondering if its balsa and you have an issue with that.

Dave - as usual - is 100% correct. If you just strengthen the areas where you see stress cracks right now, you run the risk of making them so strong that the forces are transmitted someplace far worse. One guy I know unwittingly built a literal hinge into his hull whilst trying to stiffen things up. Guess how he found that out?