I understand yoga is good for you, and I spend way too much time in Harbor Freight too! ;)
On the utilities, why can't the marina provide water to the boat. If pressure is an issue, you could get a pressure reducer. Or if it is an issue with your onboard freshwater tank, could you have a by-pass valve for onshore water, or a float valve that automatically shuts off once the tank is full?
There is a water faucet at the head of each slip. It’s up to you how you get water to the boat. My boat does not have a pressurized fresh water system. They’re available and one could be easily added to my boat. I don’t shower on board though so just haven’t done it. Our boat had one of the shower over the toilet setups so I had hubby take it out when we first bought her. Didn’t want to clean up after a shower and most marinas have adequate facilities anyway. Our marina has excellent facilities. Another thing. Our hot water heater went out about 10 years ago. I didn’t use it for anything except washing dishes so never had it replaced. I tell people I have a 12 cup hot water heater......my coffee pot. Lol. I was amazed to find out how many other people do the same thing. The one thing I require is electricity so the first thing we did was rewire the whole boat. I can shut down the dock (30 amps) before my boat shuts down. It all sounds funny but it’s really not inconvenient. You just find other ways of doing things.