I posted photo's to show the process I used to convert the incandescent fixture over the helm and those in the engine room to LED lights (the G4 pin type). I did this mainly so I could have a bi-color light at the helm, but went ahead and converted the ones in the engine room as well (especially since one of the engine room lights had a socket go bad).
The round LED's that fit a G4 (two wire pin type) light fixture can be had pretty bright so they work better in the engine room than the typical Bay15d LED. Also I have a tendency to forget to turn the engine room lights out during the daytime, and the LED's burn a lot fewer amps.
The new G4 light socket is 10 for $3 on Ebay, then all you need is a small bit of JB Waterweld to glue it to the existing light fixture. Hook up the wires to the existing switch, reinstall it and you're done!
I'm not an electrician, but it looks ok. I wouldn't completely encase the new G4 socket with the JB so it can still dissipate heat.
The whole thing is less than $1 to convert, and then you'll have to buy a $15 LED.