im heading to lowes to look at some wood soon for building the deck on a jon boat.

i know im gonna need a 4 x 8 x 1/2 to 3/4 of marine plywood.  but what type of wood should i use for the support?  

thanks

kyle

This all depends on what your plan is for the deck. A good grade of 1/2" plywood should be ample if properly  supported with stringers underneath. Remember the more plys the better. Some good straight grained 1x3 or 1x4 poplar will probably work.A slight crown of the lumber can work to your advantage. When turned up , the crown in the lumber will prestress the assembly.  Remember that it is not only possible but also desirable to make the construction light weight. This can be done  while still providing ample strength and durability for the intended use Consider the constuction of a hollow core door, very light weight for it's strength and rigidity .