Join Date: Oct 2006
Location: on the boat - Chesapeake
Thanked 246 Times in 221 Posts
Rep Power: 11
Do you plug in at the dock? Does you water heater share space with the engine? It takes a while for the outside water temp to drop. It takes longer for the water inside the boat to drop in temp.
You may find that a 100W work light left on in the engine space will make a big difference in temperature.