For REAL sailors who are REAL rum drinkers, there's only one: Mt. Gay. It goes well with coke and some like it with tonic. Always with a slice or two of lime.
Mt. Gay makes some special grades, too, one of which is a marvelous sipping rum. Definitely too expensive for mixing, but unmatchable.
Acceptable substitutes: none, really, but if you're really hard up try the Virgin Islands dark rum (Cruzan).
Definite no-no's: Pussers (you can't GIVE the sh__ away...that's why they've got the fancy mugs); Meyers (that's for mixed cocktails); Bacardi (pedestrian); Appleton's (dull); any of the "flavored" rums; etc., etc.
Some of the Martinique rums and the Haitian Betancourt Five-Star are quite good for sipping, too.
No doubt these choices will invoke some invective :-))
But, if you offer your crew and guests Mt. Gay, nobody's gonna complain!