For whatever reason (take godly intervention, that sounds best), there is no wind on this sea. The air moves, but only lazily, certainly not enough to support a navy. The prime method of movement is therefore rowing; large rowboats can navigate the Sea well. A newly developed method is the usage of enchanted golden sails, that react on the currents of magic, much like on a natural wind.
The magic here still keeps moving wildly, and old salts are able to intuit its changes, and get their boat where it is needed. Their sense of magic makes them even aware of wizards and their ilk, who, with suspicious simple folk as everywhere, will find themselves actually welcome in this region. Wizards capable of producing the enchanted sails will make a killing selling this service.
Since there is no wind, the air is much thicker with the scent of the sea. Indeed, the sea itself is thick, called smilingly a soup sometimes;just don’t drink it. But there is fish to be caught, and business to be made. It is different to be a sailor here, sailing among waves of a middling size, the occasional pirate attack or a sea monster happen to come as on every other sea. It is much quieter, though, and fogs here can last for a truly long time.
There are several islands here, most important is an archipelago in the center. The largest mountain here is a target of religious pilgrimages of sorts; wind can be felt on its mountaintop, proving that such a phenomenon exists, even to the most backwards of villagers.
Most ships are built lightly, and would make a proper sailor just sneer over the shoddy construction, that couldn’t possibly last a real voyage. But that is enough here, and valuable wood can be saved.
Much depends on whether the Sea borders on continents or islands of note, or it is a part of an ocean. In the first case, the low ships are enough to make contact with those on the shore. In the latter case are heavier, and more expensive ships necessary, ones able to sail both kinds of seas. (Note: Visitors, unless they are equipped with the right sails, or row their way through, don’t get very far here. It is likely an island with a good location will be the intermediary for much of the trade and diplomatic contacts.)
- archery is particularly favoured, and dangerous here. Most adult people can be expected to know to wield a bow with some skill. When that ship you are chasing stops rowing, you should really seek cover.