I wouldn't sail this ship if I were you
1. The Imperious Snurf. The Snurf looks rather like one might imagine a sea monster to look and no wonder: it was the original model for the monster entwined around the compass rose on ancient maps. If you meet the Snurf it will tell you this at great length, along with numerous tales of its glory days in the 12th century. If you bring it mangoes it will tell you its adventures with the other stars of the old map modelling world, including the time the Desert Lions loaded it onto a large cart and took it for a ride across the Sahara to party with the North Wind. In the modern age it is sadly underemployed. It can be easily summoned by floating a large wooden arrow, circle and/or letter ‘N’ in the Atlantic Ocean.
2. The alX'char. These beings are aliens from a planet with a high-density atmosphere. As such, their exploration of Earth has naturally concentrated on what they believe to be the most likely place to find intelligent life, i.e. the deep oceans. They regard the above-water parts of the globe as hostile environments unlikely to harbour much of interest. After three hundred years of exploration, they have largely written off suggestions of interesting transmissions from the planet as a fluke, but one occasionally encounters tourist groups who have dropped by to spot angler fish, which they believe to be the planet’s apex life form. Obviously no human has yet had a friendly conversation with them but I suspect they’d be quite interested in the prospect.
3. The inhabitants of Nether Timewell, a small village on a gently hilly part of the sea bed near Rockall. Nether Timewell was founded by humans cursed to immortality by various malign fairies. Being the sort of people who get cursed to immortality by fairies (you know the type), they were naturally curious about the new exploration opportunities available to them now they were no longer able to drown. I am not sure how, but sooner or later every fairy-cursed human who walks into the sea ends up at Nether Timewell, where there is usually a small cottage already waiting for them. The village’s extensive system of underwater lights is powered by one of only three authentic perpetual motion machines in the world and is something to behold, should you get the chance.
4. The sea itself. Although it is perfectly possible to have a conversation with the sea, be aware that you may not get an answer within a human lifetime and that it will almost certainly not be at a pitch audible by human ears. However, there are certain mystics who claim to have asked the sea multiple questions and recieved credible answers with only the minimum of translation equipment. For example, Norbertina of Amsterdam claimed to have received a full but oddly damp proof of Fermat’s last theorem in the post after discussing the matter with the Pacific from the belly of a friendly whale. If you wish to try this, the Indian Ocean may be the best one to start with. Do not attempt to have a conversation with the Southern Ocean, which is rumoured both to be unusually slow in answering and also somewhat grumpy and forgetful.
