Mastbase and cabintop blocks allow crew to raise, lower and trim sails from the cockpit. A variety of specialized blocks have evolved for routing lines aft.
Typical Boat Length:
Small Boat: 22' - 28' (6.7 - 8.5 m)
Midrange: 29' - 34' (8.8 - 10.4 m)
Big Boat: 35' - 42' (10.7 - 12.8 m)
This simple system leads principle halyards aft. Used by boats under 9 m (30 ft).
Larger boats use special mastbase halyard lead blocks. Lines are routed out to deck organizers then aft to stoppers and winches. Stand-up blocks on a base are sometimes preferred for their complete articulation, but they hold halyards higher off the deck than specialized mastbase blocks.
Modern race boats lead halyards and control lines straight aft through deck organizers so they can be used on either cabintop winch.
Special “over-the-top” blocks are required to route lines over an outside corner like the front of a doghouse or coaming.