On the subjects of windows & fire monitors on the 46 inch boat I have had some success. I put detailed pictures & building tips on my website, so I wont repeat all of that here.
I tried lots of methods for the windows, but in the end plasticard frames stuck over clear perspex (the kind that most kids toys come in) worked out best. These are screwed on rather than glued.
The fire monitors I managed to scratch from scratch using brass tube - soldered with a domestic soldering iron - and beleive it or not, some old wooden golf tees (they are just the right shape for the nozzle). Both monitors move and fire water - about 10 feet (3m) thanks to a couple of 12v fuel pumps. I used the Robbe system to make them turn.
I ended up radio controlling lots of things in the model including a swinging, wiching jib and search light. The result is a boat that weighs 25 pounds and with a 10cc engine goes like a rocket. But you have to be careful on the corners - as there is a risk of tipping it over.
The site can be found on:
[link]http://pic6.piczo.com/fireboat[/link]