@Dr. D , can you please take a shot looking into the head from outside the head door. Try to show the location of the head (toilet) relative to the sink.
The condition of the area below your sink is incredible. I have maintained the condition of that area in my boat to as as new from when I received the boat and it doesn't look anything like yours. All bare, unfinished fiberglass.
I am losing sleep thinking of anything less than perfection going into your project. The cost of replacement hose is immaterial as it runs about $1/foot. I don't believe removing any hoses is necessary to rinse the lines to the head each time you leave.
The condition of the area below your sink is incredible. I have maintained the condition of that area in my boat to as as new from when I received the boat and it doesn't look anything like yours. All bare, unfinished fiberglass.
I am losing sleep thinking of anything less than perfection going into your project. The cost of replacement hose is immaterial as it runs about $1/foot. I don't believe removing any hoses is necessary to rinse the lines to the head each time you leave.