Include a boat, any sort of boat, perhaps one of these -- canoe, cedar strip runabout, Sea Flea, yacht, tall ship, pedal boat, sailboat, cruise ship, tanker, Aqua Car, warship, junk, ferry, tugboat, Dippy, boat made out of a bathtub, kayak, submarine, houseboat, Dragon boat, dory, barge, shipwreck, inflatable, lifeboat, gondola, hovercraft, ocean liner, riverboat, dinghy, canal boat, rowboat -- in your piece of writing. Maybe your character lives on a boat or is afraid of boats or has never been on a boat and likes it that way. Perhaps your character builds boats or dives to shipwrecks. Or tell your story from the boat's point of view, a barge who is sick of carrying heavy loads and wants to just see what it would feel like to go as fast as he can across the open water or a tugboat who wishes she could just once go beyond the harbour. Maybe your character gets seasick or is fine on the water but can't stand to be on dry land because it makes her feel queasy if what's under her feet isn't moving and she can't smell the sea. Write about a particularly rough crossing on a ferry or a becalmed sailboat. Maybe your character was a privateer or sailed with Ireland's Pirate Queen, Grace O'Malley. Perhaps your character lives in a house that is shaped like a boat and has everything stowed in cupboards with latches and on shelves with edges, everything battened down in case of heavy weather. Perhaps your character races boats for a living or gets lost at sea or is shipwrecked on an island with only his collection of teacups and his wits.