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 e
xisting 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.