Abstract: A pole support is adapted for use in a mast assembly of a sail craft to selectively adjust tension of a sail. The mast assembly comprises an elongated and rigid tubular member having a central longitudinal axis and a surrounding sidewall defining an interior therefor. The tubular member has a base portion adapted to engage a mast foot and an upper portion sized to slidably engage a mast pole. A selectively actual drive mechanism includes a lift structure which is operative to support the mast pole and upon actuation of the drive mechanism to adjustably vary the effective length of the mast assembly by moving the mast pole further from and closer to the base portion, thereby to respectively increase and decrease tension of the sail when the tack is secured to the mast foot. The lift structure may also include a collar slidably disposed thereon, which collar has a neck to provide a first protective spacer between the mast pole and the tubular member.