Can't remember exactly but Curacao and Port of Spain usually have a small tanker, T2 or two and small merch parked there. San Fernando I think had the same. However, it's very shallow there with warships and planes a plenty, so you may want to reconsider it
Curacao is 'guarded' only by an unarmed trawler ( a bug?) making it easier. These ports are very tight, so you'll get a bit awkward shots, therefore you'll be better of hunting out in the open waters.