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Lifeboat safetyLesson 4 of 8

Hooks and release gear

On-load and off-load release, the hydrostatic interlock, why a hook must be completely reset, the 2014–2019 hook replacement and fall preventer devices.

14 minutes · For signed-up learners, free · Rules checked 20 October 2026

Fall blocks and hooks hanging from a davit under a yacht's deck
From our group's annual rescue boat and davit inspection in Fiji, September 2026.

In plain words

A lifeboat lowered by a davit hangs from two hooks, one at each end. When the boat reaches the water, the crew open the hooks so the boat can get away. That is the release gear.

There are two ways to open the hooks. Off-load release works only when the boat is afloat and the weight is off the hooks. On-load release can open the hooks while they still carry the boat’s weight. It exists for emergencies, when the weight may not come off the hooks.

On-load release is powerful, and that makes it dangerous. If a hook is not fully closed and locked after use, the weight of the boat can force it open. People have died this way.

So every hook must be completely reset, and you must check it every week. Always follow the manufacturer’s manual for your own gear, because designs differ.

Key points

  • Off-load release frees the boat when it is waterborne or when there is no load on the hooks; on-load release frees it with a load on the hooks (LSA Code 4.4.7.6, MSC.320(89)).
  • On-load release must have a hydrostatic interlock, unless other means ensure the boat is waterborne, and an override for emergencies that is protected against accidental use (LSA Code 4.4.7.6, MSC.320(89)).
  • On-load operation “shall require multiple, deliberate and sustained action or actions by the operator” (LSA Code 4.4.7.6, MSC.320(89)).
  • On-load release mechanisms not meeting the new criteria had to be replaced by the first scheduled dry-docking after 1 July 2014, and no later than 1 July 2019 (SOLAS III/1.5, MSC.317(89)).
  • For lifeboats installed on or after 1 January 2026, “the hook shall not be able to support any load unless the hook is completely reset” (LSA Code 4.4.7.6.8, MSC.554(108)).
  • The weekly inspection includes the on-load release gear “being properly and completely reset” (SOLAS III/20.6.1).
  • “No maintenance or adjustment of the release gear shall be undertaken while the hooks are under load” (MSC.402(96) §6.2.4).

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The rest of this lesson, the interactive Reset a release hook and the quiz are open to signed-up learners. It's free, takes a minute, and opens every lesson in all 14 courses.

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Sources

  1. Amendments to the LSA Code (release mechanisms, 4.4.7.6)IMO resolution MSC.320(89), 20 May 2011, in force 1 January 2013
  2. Amendments to SOLAS (hook replacement, III/1.5)IMO resolution MSC.317(89), 20 May 2011
  3. Amendments to the LSA Code (hook reset, lowering speeds)IMO resolution MSC.554(108), 23 May 2024
  4. Amendments to MSC.81(70) (hook tests)IMO resolution MSC.321(89), 20 May 2011
  5. Adoption of amendments to SOLAS 1974 (new chapter III)IMO resolution MSC.47(66), 4 June 1996
  6. Amendments to SOLAS (weekly and monthly inspections, III/20)IMO resolution MSC.152(78), 20 May 2004
  7. Requirements for maintenance, thorough examination, operational testing, overhaul and repair of lifeboats and rescue boats, launching appliances and release gearIMO resolution MSC.402(96), 19 May 2016
  8. Review of Lifeboat and Launching Systems' AccidentsMAIB Safety Study 1/2001, 1 February 2001
  9. SOLAS evaluation of lifeboat release and retrieval systems (MSC.1/Circ.1392)West P&I
  10. Survival Craft, Rescue Boat and Launching Appliances – Testing, Servicing and MaintenanceLiberia Marine Notice SAF-005, Rev. 07/26
  11. IACS UI SC 281 (single fall and hook systems)IACS unified interpretation, copy published by Türk Loydu
  12. STCW Code Table A-VI/2-1IMO STCW Code, copy published by EduMaritime
  13. ABS Regulatory News: Brief MSC 111ABS, 22 May 2026

Free awareness training. Al Safwan Marine is not an approved training provider, so no certificate is given, and these courses are not a qualification. They don't replace STCW training, manufacturer training or the certification technicians need for this work. The manufacturer's manual and your flag's rules always come first.

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