wax - Surfboard wax, which is rubbed onto surfboards and paddleboards for traction (n); car wax, which is put on the hull of surfboats to reduce friction (n); to put wax on a board or boat (v)

wear blocks - The wood blocks attached to the gunnel of a boat to form part of the oarlocks (n)

wet suit - A neoprene suit worn in the water for insulation which works by trapping water and allowing the body to warm it (unlike a dry suit, which keeps water from touching the body) (n)

white cap - A rough-water swell that peaks violently and forms a top with white foam (n)

whistle - Four blasts of a whistle, used to system call for backup when the radios do not work properly (n)

whitewater - The water that remains in motion after the wave breaks (n)

windward - The side of an object that corresponds to the direction the wind is coming from (adj); Antonym: leeward