Moveably mounted on the deck or decks is {HEAD ~ a series} of {TAIL ~ mobile boat supports} that move back and forth between an inoperative position and an operative position 
Moveably mounted on the deck or decks is { HEAD ~ a series } of { TAIL ~ mobile boat supports } that move back and forth between an inoperative position and an operative position
OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH