I thought this was going to be a weird fetish thread so steered clear

Do you mean a long board, my quad is okay, it's in the tak thread, I also have a 7'2 single that gave me many years service and goes well in sucky waves
But this is the LB forum so For me if it is sucky you need to lose some bulk, you dont need the nose width cause you wont be up there as much and you want it be able to turn hard of the back and generate speed off the bottom.
maybe something like 9'0x 22 -22 1/2 x 2 5/8 - 3/4 , narrow nose (18-20), pulled in tail (14-15). I guessed these so might change them.
I would go a bumb squash in the tail, pin will draw your turns out a bit more, where the square will turn sharper. Also id get it thinned out in the nose and tail and a hard edge on the rails in the last foot to 2 foot. Glass it reasonably heavy.
Fin wise.. Surf it with reasonably large sides and a 6 inch ish middle.. The big sides will produce the drive and also help hold in when turning through a sucky section. A big single will hold in heaps better on drops but you won't get as much speed of the top.
Th above is pretty much my everyday board, except I have a pin tail. I don't have any photos but I'll take some and post them up.