Zendarin,
I believe you are on an island whose /loc is approximately -1696 +2400. You
should put jig on and swim to the Sister Island whose coordinates are +211
, -9190. You can do this, I have done it many times. The boat docks here
right after it zones from Freeport. Just so you know you are on right
island there are many Sister of Errollsi (sp.) guarding and some dwarfs.
Nothing on this island will attack you. Just keep checking the /who and
when you see people in zone ask one of them or shout where is the boat.
Don't get frustrated swimming, you will get there, and it's a great way to
raise your swimming skill.

Good luck,
Infiniti