3/8 ID hose for dripless

[Rogerh]

On my last check of the boat before exiting her for the hurricane I opened the engine room door and could hear a very good water spray/run. Long story short one of my dripless cooling line that up the cold water exhaust feed was spilt wide open. It was split way below the waterline. I looked on line for what kind of hose to use for this but since its so small all I saw was fuel line hoses. This is a critical hose so I want to make sure I replace it with proper hose. Any suggestions?
Second question, when this first happened we thought it was a split/crack in the muffler. the exhaust exits the boat through a stainless 12 inch flange. It's about 1/4 below the water line. In an emergency like I thought I had, I would need to plug this 12 inch hole in either side of my boat. Thought a plug would be easy to find. No luck so far. Any suggestions?
Thanks much!

 

[Rogerh]

Exhaust port plug

 

[jleonard]

I used fuel line hose for mine and after 11 years it is still fine.

 

[O C Diver]

Heavy marine fuel line when I replaced mine.

I have a big pile of towels and heavy plastic sheet. Ball the towels into the center of the plastic, jam the platic with towels into the pipe and keep jamming more towels in behind it until you can't. Would probably secure it in place with a few ropes crossed over the pipe and held in place with a few hose clamps on the pipe.

Ted