Something like this would do. You could even add lights or anything else down the road by just running my wires into your Block.
http://www.westmarine.com/buy/sierra...ang-6--4629077
This could be another solution.
http://www.autozone.com/ignition/ele...al/510827_0_0/
Just make sure whatever you decide to get some marine grade shrink tubing. Harbor freight has a good deal on a box of that stuff. Dielectric grease should also be used to prevent any corrosion. Let us know how it ended up coming out.