There are lots of islands with really cool places and caves mostly used for tall tale voyages, maybe a random couple of isles could be filled with skelletons protecting an special item or making a small ritual. that gives you more reasons to explore every part of the isle and also gives the feel of a more dynamic world.
Maybe encountering skellies in different suspicious situations that if you wait for full animation it opens a secret hatch or cave.
Create events that triggers when you reach to a specific zone, that would be different and new in comparison to other activies you can do in the game, world events appear in clouds and you know what is going to happen, with voyages you get the name of the island and the mission type, there is nothing to get surprised about besides skelly kegs of couse. but if you could have the chance to step into ramdom special mini events with cool loot by just exploring the game it would be just lovely.
