if you have the spare cashola run
pvc, theres also gel filled wirenuts that will help as well.
Get the nice sealed gray junction boxes too like in dfisch's
DIY, they're a little more but once again well worth it. You can slap together a cheapo hack job or do it nice and tighty righty with a few extra $$ Personally I'd rather spend the few extra especially considering the wonderful conductivity properties of salt water
