When we bought the boat the shower looked OK. The previous owner said it had been refurbed when he had purchased the boat.
The refurb had been done using some laminated mdf material, it had been installed OK, but along the back of the shower the hot and cold pipes had been run through and then boxed in with the same laminated material. This is where the problem was, the joints had not been sealed properly and water had got in, the mdf had expanded and was useless.
The shower enclosure is a hardwood custom shower enclosure. The basic framework was OK but the bottom of the frame where it meets the shower tray was rotten, also the deflector on the bootm of the door. I managed to engage a carpenter to remake these parts in a similar hardwood. I then sanded down the whole framework back to base wood and refinished.
These pictures show what was behind the laminate.
On the right on these pictures is where the plumbing is, there was a glass partition between the shower and the towel rack, this let light through from the shower to the towel rack.
I removed the glass and replaced with an acrylic semi transparent panel.
I replaced the mdf with some more acrylic, we purchased this from http://www.splashacrylic.com/, this was a brilliant company, they help with the measurments and cut the acrylic to size.. I felt that acrylic was better than mdf as its waterproof and cannot expand if water did get to it.
I changed the plumbing so I only needed one pipe in the shower cubicle. This was done using a household electronic mira shower mixer. It meant the hot and cold stayed out of the shower enclosure and only the output pipe came through. The control unit was also wireless so that needed no connections.
I sealed all around with some mould resistant sealant to finish off.
Overall we are really pleased with the finish, a year on it still looks great
The only other modification I did was to add a flow switch into the output pipe, when the water is on a switch contact is made, this is fed through to a timer relay that connects to the shower waste pump. When the water stops the timer runs for another 20 seconds to empty the tray.