Hi CaitB and welcome to the forum.
Hot water of course can be done but depending on your current
setup and equipment
may be easy or hard, cheap
or expensive so maybe a little more information.
From your question I'm thinking you want a system that works like a house, that is you turn a knob in some way and hot water mixes with the cold coming out of the faucet at the sink (and shower
?) like a home water system.
First question, does the boat have second pipes or hoses of some kind running to all the places you want hot water? If not, part of the project
will involve running a second hose/pipe next to the existing cold water lines.
Next, do the faucets in place already have places for a hot water line to hook up or do you have single
faucets? If not, then you have to switch the singles for a two line faucet or install a second single
Once you get past these, how to make the water hot. Four common ways, engine
, gas, solar
heat you run a fresh water line into a place on the engine's heat exchanger
(some engines come with the adapter installed, some you might have to order a part). You run the engine until it gets hot and it heats the water in your hot water tank.
and gas work like home units but each has issues. Electric takes a LOT of power so you can use it at the dock
, run a generator
or have a LOT of battery
power and a way to recharge them. Gas you have to vent, store the propane
, add safety
systems so you don't blow up the boat, etc.
you have to add a lot of plumbing
lines and don't get much on a cold, cloudy day.