posted 06-25-2008 07:21 PM ET (US)
Fabricating your own wiring harness should not be difficult if you can--locate the proper connector
--have the proper gauge and grade of wire in the proper color insulation
--have the necessary tools to assemble the connector
Many marine electrical connectors are molded-on to make a better seal, and, even if you can find a mating connection, the field-installed connector won't be waterproof.
Personally, I would get a new VHF Marine Band Radio with included digital selective calling with at least a Class-D rating. You can get a new VHF Marine Radio with Class-D DSC for about $130, and it will include a wiring harness and mounting bracket.