Hi  LAL et al; A bit off topic but in the past doing our ocean stuff, I have used a black mastic liquid sealer. I used it on all the connectors to prevent the salty air getting to the wires. This is a very, very tedious job. If your electrical and electronic panel is well designed it does make the job less intensive.  You need a steady hand so you do not slop the stuff where it is not needed.. Doing it at anchor or on the hard is recommended. Another  hindrance is that the temperature to apply is 50 to 90 degrees. Once the mastic is cured (24 hours) the temperature is not a factor (-50 to + 500 degrees} As I said, off topic and for what it's worth. Leonard Stern, INDIFFERENCE