Ladder building material

[abl1111]

I want to build a small ladder for my 23' Tsunami - it allows you to go from the cabin to the bow - quickly. I have the original ladder that is made out of a really light-weight moulded plastic ( mine cracked in a really b*tchy spot that cannot be replaced )

I want to copy the original design because it allows the ladder to hinge/swivel closed on itself and stow easier than a fixed style.

The question: What is a really lightweight material that is strong, maintenance freeand easy to work with ? i.e. the properties of wood, but lighter ? Starboard might not have the needed strength to hold bolts laterally...

Thx