There is nothing available for marine engines.
Some of the local fishermen up here in Maine use an automotive block heater that plugs
into 110V shore power and keeps the oil warm. I am always a little nervous about this
as it is not explosive proof. The heater is usually stuck down the oil dipstick
There is also a block heater (again automotive) that heats the anti-freeze with a coil
that is put into where a plug is. Again it runs on 110V and is not officially explosive
There is also a company out of Wisconsin (or Michigan) area that makes a propane heater
for marine use. It is not a block heater, but the idea is that it keeps the whole
engine compartment above freezing.
You can also look at a company Espar company that has a heater that runs off the
engine fuel (diesel I think mostly, but they may have a propane or a gas version).
We don't handle any of these I am afraid, but we can supply you any parts for your engine
Hope this helps.
J. D. Neeson
Marine Parts Express
Toll Free: (877) 621-2628
International: (207) 882-6165
Fax (207) 882-9865