No knots needed: how St Mary’s lifeboat towed a yacht to safety

Somewhere out in the dark north of the Isles of Scilly, four people were sitting on a yacht that would no longer steer. The fix came from a lifeboat, a very long yellow rope, and a small blue loop that looks like a knot but does a job no knot on board is trusted with.

A late-night call north of St Martin’s

The RNLI crew at St Mary’s were paged by the Coastguard at 10.40pm on Tuesday 22 September. A yacht with four people on board had suffered a hydraulic failure that took out its steering, 4.5 nautical miles north of St Martin’s Head.

It was the station’s 25th shout of 2026.

📷The lifeboat's track out to the yacht and back into St Mary's harbour. Credit: St Mary's RNLI Lifeboat Station

The long way round

With the tide at low water, the lifeboat could not take the direct route. Instead it headed round to the south of St Mary’s and then out to the yacht.

Once on scene the crew set up the towline and passed it across. The yacht was then towed back at between 5.5 and 6 knots into St Mary’s harbour, where it was safely secured onto a visitors’ mooring.

What waits on the lifeboat’s aft deck

After the job, St Mary’s RNLI Lifeboat Station shared a look at the purpose-made towing kit the lifeboat carries, all of which has a safe working load.

The main towline is 200m long and 32mm in diameter, made of polyester. It is yellow, and by the crew’s own account it is heavy. Each end has a spliced eye, and the line is rated to 22 tons.

From there the crew work with bridles and pennants, which also have eye splices and are colour coded so they are easy to set up. These are all made of Dyneema. The bare grey bridles are rated at 22 tons. There are also two 5m orange pennants and two 15m pink pennants, which have a protective cover over them and are rated at 40 tons. Those bigger pennants come out for larger vessels.

A blue loop where you’d expect a knot

None of these lines are joined with knots. Instead the crew use blue soft shackles, each rated at 22 tons, which open up and close again to form a loop that links the towline to the pennants and bridles. The one in the photo is one of them.

The station describes them as very simple to use but very effective. And the colour coding earns its keep when conditions are at their worst. On dark, wet and stormy nights on the aft deck, knowing at a glance which line is which makes for a cleaner and safer deck when the crew are handling lines.

Stronger than the boat pulling it

Every piece of the kit is rated so that it is stronger than the lifeboat’s actual bollard pull. In other words, the rope should never be the weak link. For St Mary’s, with its Severn-class lifeboat, that pull tops out at 10 tons.

📷One of the blue 22-ton soft shackles St Mary's lifeboat uses to join its tow lines. Credit: St Mary's RNLI Lifeboat Station