"Unsinkable" is a contradiction of terms, as the "Titanic" proved.
craft?
Dead reckoning is a method of estimating the position of an air craft or ship.
A ketch is a type of sailing craft.
You cannot craft a sponge. They were unobtainable until 1.8, but now they can be found in ocean monuments.
Modern day sailing is recreational, and harnessing the power of the wind to accelerate and direct a craft in almost any direction can be stimulating and enjoyable (unless you are in Jaws 2, then it is not so much fun).
We cannot live
You cannot craft a mailbox without a mod (modification) or a server plugin.
In the UK there are "Dinghy Sailing Magazine" and "Yachts & Yachting". Both provide excellent commentary on small boat current affairs. A: In the US look at SMALL CRAFT ADVISER and MESSING ABOUT IN BOATS.
you cannot craft one, you will need to make it using your imagination using blocks etc
The general rule is powerboats give way to sailboats, as sailing craft are generally less maneuverable.
Fly.
The sail is the tool that uses the wind for power. The tiller or wheel is the tool that controls the direction of the craft.