A standard Harken ratchet block has a manual on/off switch, so you decide when the sheave grips; a Ratchamatic engages automatically under load and free-spins when the line goes slack. Choose a switchable ratchet when you want control across different crew and conditions; choose a Ratchamatic when you want automatic hold while trimming and free release when you ease.
Ratchet vs. Ratchamatic at a glance
| Standard (switchable) ratchet | Ratchamatic | |
|---|---|---|
| Engagement | Manual on/off switch | Automatic, load-sensing |
| When ratchet is "off" | Spins freely both ways (plain block) | Spins freely whenever the line is unloaded |
| When loaded | Grips only if you switched it on | Grips automatically; releases when slack |
| Best for | Mainsheets; mixed crew strength; full control | Asymmetric spinnaker sheets; dinghy sheets; hands-on trimming with quick release |
| Example products | 2135, 2136, 2608 | Flip-Flop 2144/2145; Power3 2165/2168; HTE 2625 |
What does a ratchet block actually do?
A ratchet block has a toothed sheave that, when engaged, only turns in one direction. That lets a trimmer hand-hold a heavily loaded sheet—the teeth add grip and multiply your holding power by roughly 10:1 (per Harken), so you can hold and ease a line you could never grip on a plain block. The trade-off is a little drag while the sheet runs.
How does a standard switchable ratchet work?
A switchable ratchet has a small lever to turn the ratchet on or off. Off, it behaves like a normal free-running block. On, it ratchets and gives you holding power. Because you choose, the same block can suit a strong trimmer who wants free running or a lighter crew member who needs the grip—handy on club boats where different people sail the same hull. It's the classic choice for a dinghy or small-keelboat mainsheet, where you want predictable, controlled behavior.
What is a Harken Ratchamatic?
A Ratchamatic is a self-tending ratchet: an internal load-sensing mechanism (Harken's "Flip-Flop") engages the ratchet as soon as load comes on the line and disengages it the instant the line goes slack. You get automatic holding power while trimming, and the sheave spins freely the moment you ease—no switch to flip. That makes it ideal for an asymmetric spinnaker sheet: trim by hand, then let it run cleanly through a gybe, and it re-engages the moment you load up again.
What are Power3, HTE, and grip ratings?
Power3 is Harken's adjustable Ratchamatic—it lets you select how much holding power you want rather than living with a single setting. HTE (High-Tech) versions use lighter, higher-strength materials for performance boats. Grip ratings—standard, 1.5x, and 2x—describe how aggressive the sheave teeth are: more grip means more holding power for heavier loads and bigger boats, at the cost of a touch more friction.
Which should I choose?
Pick a switchable ratchet when you want to decide moment to moment—mainsheets, mixed-ability crews, or any line where you sometimes want free running and sometimes want grip. Pick a Ratchamatic when the ideal behavior is "grip when loaded, free when eased" and you don't want to think about a switch—classic for asymmetric sheets and many dinghy applications. If you want both grip control and automatic behavior, step up to Power3. Match block size and grip to your line diameter and load.
Frequently asked questions
What is the difference between a Harken ratchet and a Ratchamatic?
A standard ratchet has a manual on/off switch you control; a Ratchamatic engages automatically under load and releases when the line is slack, with no switch to operate.
When should I use a Ratchamatic block?
Use one where you want automatic holding while trimming and free release when you ease—most commonly an asymmetric spinnaker sheet or a dinghy sheet that needs to run out cleanly.
When is a switchable ratchet better?
When you want full control, such as a mainsheet, or on a boat sailed by crew of different strengths who each prefer the ratchet on or off.
How much holding power does a ratchet block add?
An engaged ratchet sheave can multiply holding power by roughly 10:1 (per Harken), and higher grip ratings (1.5x, 2x) add more for heavier loads.
What does the grip rating mean?
Grip describes how aggressive the sheave teeth are. Standard grip suits medium-to-light loads; 1.5x and 2x grip provide more holding power for bigger boats and higher loads.
Can a Ratchamatic ever run out too fast?
On some setups, like a Laser mainsheet, sailors prefer a switchable ratchet because a Ratchamatic releases very freely; a standard on/off ratchet keeps a little controlled drag.