I second the suggestion for animals and their ambience in the world. Dolphins, fish, birds.
Birds may make a fine clue that you are near land as well and dolphins may make fine company when bored and sailing windward.
I live for nautical music, thank you for this thread. <3
I haven't had the best luck but I managed to find a French Canadian group a few weeks ago of a modern fusion with a familiar sound you may like.
https://youtu.be/yfBOpYkd89o
Great posts. ;-; Love to read about shipwrecks, morbid as it is. Just sort of interesting to think about all the beauties laying on the sea floor. With every ship lost, that's one less we would have potentially been able to enjoy for longer. Ahhhhh