tail - The back end of a paddleboard (n)

thermocline - A curve separating the warm water near the surface from the cold water near the bottom (n)

thole pins - The U-shaped metal pieces attached to the wear blocks on a surfboat (n)

tide - The periodic variation of the surface level of the ocean and bay due to the gravitational pull of the moon (n)

tide table - A chart that lists the times of high tide and low tide for each day of the year (a new table is needed every year) (n)

torpedo buoy - The same as a rescue buoy or rescue can (n)

transom - The flat, slanted part at the stern end of the boat (n)

treading water - A technique used to keep the same position in the water and to keep one’s head above water; it involves kicking with the feet and sculling with the hands (n)

trim - Balanced in a way that allows an object to move across the water efficiently (adj)

triple - A beach with three guards working that day (n); a beach with three guards at the current time (n)

trough - The area in front of the face of the wave, where the water is shallower than surrounding water (n); an area of deeper water inside a sandbar (n)

tube - A wave that breaks in a way that forms a hollow tunnel (n); to break in a tube (v)