I don't have much to say here, except DO NOT use household Romex Cable (solid copper wire). The solid wire will eventually break due to a boats vibrations. Stranded wire must be used (that is appropriately rated for the voltage), and of course tinned marine wire is greatly preferred.
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"Knot Easy" 2000 Horizon 240 Volvo 5.7GS /SX
tow: 2017 Honda PILOT EXL-AWD
prev. boats:
'87 Chaparral 198CXL 4.3 OMC Cobra
'69 Jetstar 16ft Ski Boat, 115hp Yamaha
'68 Aluminum Jon Boat, 3hp Sears
'64 Water Wings