Inboard rhymes with:
onboard, aboveboard, baseboard, billboard, blackboard, cardboard, checkerboard, chessboard, chipboard, clapboard, clipboard, containerboard, dartboard, dashboard, fiberboard, fibreboard, fingerboard, floorboard, hardboard, headboard, keyboard, linerboard, mopboard, onboard, outboard, overboard, paperboard, pegboard, plasterboard, pressboard, scoreboard, seaboard, shipboard, skateboard, smorgasbord, snowboard, springboard, storyboard, surfboard, switchboard, wallboard, washboard
Inboard sounds like:
impaired, impart, imparted, imperato, import, imported, impurity, inbred, inbreed, inebriate, inebriated, inferiority, inferred, infrared, infuriate, infuriated, invert, inverted