Bow and Wave
The navigation center where ships are operated from is called the “wheelhouse,” also known as the “pilothouse” or “bridge” on larger vessels. Hence, to say someone is “in your wheelhouse” means that they are in a place you control or feel comfortable in.
A very drunk person is often described as “three sheets to the wind.” Another great nautical idiom, the “sheets” here refer to the ropes which held the corners of a sail in place. Any ship with three untied corners of a square sail flapping in the wind had serious control and navigation issues, just as a big drunk might.
Boat speed is measured in knots, which means nautical miles per hour. This is similar to miles per hour in land speed, but not exactly; one knot = about 1.151 mph or 1.852 kph.