Matthew Sheahan takes a look at some of the key findings of the Marine Accident Investigation Branch from a report following last year’s tragedy in which all four crew were lost


The issue of grounding is one that will ring alarm bells among the wider sailing community as there can be few sailors who have not at some point hit the bottom. The MAIB findings and analysis draws attention to how seriously we perceive the potential for damage and how light groundings can cause more damage than you may expect. The report states;

A skipper’s perception that the force of a particular grounding is insufficient to raise concern does not necessarily mean that significant damage has not occurred to the keel and/or the vessel’s structure.

Considering the potential for the hull and matrix to become detached from each other as a result of grounding, and the difficulty with detecting such detachments on vessels constructed in this way, it is possible that some of Cheeki Rafiki’s reported ‘light’ groundings could have significantly affected the integrity of the matrix attachment in way of the keel. Furthermore, it is possible that additional unreported

‘light’ groundings occurred, further increasing the likelihood that the keel attachment structure had been weakened.

When it comes to assessment of the damage and repairs the report rings yet more alarm bells. ‘There is no industry-wide guidance available which sets out a method of detecting matrix detachment,’ it states.

On one occasion Cheeki Rafiki was temporarily rested on its keel to enable signs of hull deflection after a grounding in 2007 but the report says that, ‘it is unlikely to be sufficient to identify areas where full detachment has not occurred and some bonding exists.’

The report also highlights the subjective nature of testing using a hammer (to tap around joint areas to listen for hollows) and describes how high rig tension can affect the findings.

In the case of Cheeki Rafiki the report suggests that, ‘it is possible that detachment had also occurred in way of the keel but had not been detected because of the clamping effect of the keel bolts, the keel not having been removed.’

If you want to check the integrity of your yacht’s keel,  read Matthew Sheahan’s self-help guide here.

More on this topic: We investigate keel failures and what you can do to prevent them

  1. 1. Introduction
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