Harken has put together a nice video that explains the difference between a ratchet block and a ratchamatic block.
the main difference is that the ratchamatic blocks are load-sensing and have a “ratchet that instantly engages when a predetermined load is reached. When unloaded, the ratchet pawl seamlessly disengages to allow the sheet to run out instantly during mark roundings and jibes. The Ratchamatic allows lightly-loaded sheets to run freely in both directions for fingertip control” (source: Harken Q&A)
Sunfish sailors often use one of the following blocks for their mainsheet control:
- Harken 2135 (ratchet block)
- Harken 2625 (ratchamatic block)
I’ve traditionally used the 2135 (shown here on my mainsheet controls upgrade post), as it is usually cheaper, and the switch is usually easy enough to reach if I wanted to release the ratchet mechanism to allow the line to run freely. for a Sunfish sailor looking to race, the 2625 might be a better option as it will let the mainsheet out easier when your time spent changing tacks could make the difference in a race.
h/t: @harken
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