An old retired sailor

[ruger#1]

An old retired sailor, puts on his old uniform & heads for the docks once more, for old times sake.

He engages a prostitute & takes her up to a room.
He's soon going at it as well as he can for a guy his age, but needing some reassurance, he asks, 'How am I doing?? '

The prostitute replies, 'Well, old sailor, you're doing about three knots '

'Three knots?' he asks. 'What's that supposed to mean? ?'

She says, 'You're knot hard, you're knot in, &
You're knot getting your money back !