Grab, Barry is right--the spanker is a fore-and-aft sail set on the farthest aft mast of a squarerigger. It is not necessarily the highest sail on the aft mast. Balclutha (a full-rigged ship) has on her mizzen a spanker, a crojack, lower and upper topsail, topgallant and royal. Only the spanker is fore-and-aft; the others are square, and all but the crojack are more or less above the spanker. Pamir(a bark),pictured in your link, simply has multiple spankers at different levels. That's what makes her a bark. Cool link, by the way. Also, cool info on Admiral Vernon re: Mount Vernon.

Since Amos started out by answering practically everything, I'll go for some of Amergin's: a bowline is used for practically anything where you want to tie a line to something with a really secure knot, such as tying a halyard to a sail in a small boat.

A short splice is when you join two pieces of line together by weaving the strands of each into the twisted strands of the other in the opposite direction from the lay, resulting in sort of a long bump in the line. When you pull on the line, it actually tightens. It's stronger than a long splice, but because it creates a lump, it won't go through a block. So for that you would use a long splice, where you twist the strands together with the lay. If it's well done, you can hardly tell where the rope is joined.

You would probably use a sheet bend to tie a heaving line to a mooring line.