Yea, the space under is nice. It's an 18ft Naughty Star. Puttin 4 marine Kicker 6" speakers in there running off a marine amp. I already had them on my aluminum boat so I am still in the process of building an overhead speaker box to hold all 4 speakers. Here are some in process pics. All thats left is to spray it in bedliner and run the speaker wires. There is a good 3 layers of fiberglass and its pretty solid but light.

http://www.freeimagehosting.net/uploads/98be98d8d4.jpg
http://www.freeimagehosting.net/uploads/5d1f4d414f.jpg
http://www.freeimagehosting.net/uploads/8be3a0b5fa.jpg
http://www.freeimagehosting.net/uploads/750344bc56.jpg
http://www.freeimagehosting.net/uploads/414bcb5885.jpg

The pics don't show the contour lines too good but hopefully I'll finish up here soon and it will be white so you will be able to see the curves alot better. Gonna try and find someone to spray it in white bedliner.

Hell yeh man that dont look bad at all!

But let me shine some light on this bed liner thing, white colored spray on bed liner is poo! The white will turn yellow before you know it, now what i did in a show truck i built a few years ago is Spray the bedliner and let it dry once dry and untouched spray a base coat/ clear coat on it and you want have to worry about any fading or dulling out it will stay nice and shiny white! It holds up a little better than you would think ill try to find a pic of my truck bed somewere.

Here ya go the fuel cell and side rails are done like I explained above, hope this helps!
http://sphotos.ak.fbcdn.net/hphotos-..._2702789_n.jpg