Time to look for possible routing paths that will work. Id like to think a boat that size has some tubes for running things like wires and hoses but who knows. Like mentioned fish tape maybe? I have a long piece of 6 and 8 gauge wire I use as fish tape it’s really rigid and you can bend the end to help make it go the direction you want I’ve worked some things in place with it that fish tape won’t work in because its not stiff enough. You might find a piece in a rebuild it center cheap. You could try lubing it and your new hose with soap or maybe the lube electricians use when pulling wires in conduit. Make sure it wont harm the rubber first. What ever you do don’t over stretch your new hose when pulling on it and make sure your hose will withstand uv and ethanol.
