Sea anchors

Introduction.

In the chapter ‘Storm strategies’ in the online book ‘Handling heavy weather’ we divide the possible strategies to adopt into two groups: ‘wind´s up the storm’ and ‘running off the storm’.

‘Wind´s up’ implies that the boat will face the gale by receiving the wind and sea from the bow (or between the bow and the tack); while “running the gale” implies receiving the wind and waves from astern (or between astern and the stern).

In another chapter we saw the manoeuvre of ‘heave to (hove to)’ in a gale situation. However, depending on the type of boat and its weatherworthiness, and especially when conditions deteriorate into a heavy or heavy gale, the ‘heave to’ manoeuvre may not be sufficiently effective. There may also be insufficient distance to shore downwind (sea room) and it may be necessary to stop the boat at sea.

Storm devices that are deployed at the bow are generically called sea anchors. The sea anchor is a device that is dropped into the water and attached to the bow of the boat by means of a long, strong line. Due to the greater resistance of the sailboat, it will theoretically align its centreline with the wind and the sea, while it is practically stationary or drifting very slowly.

This technique has been used on numerous occasions on fishing boats and also on sailing yachts. However, in the case of a sailboat, the likelihood of success of this technique depends on several factors, such as, for example:

– The type of sea anchor and its ability to stop the boat or drift. The two most common types of sea anchor are the cone-shaped and the parachute type (as shown in the figure above).

– The design of the ship, the shape of the hull and superstructure, and its displacement; which can either favour or severely limit the possibility of a ship being aligned in the wind and sea with a sea anchor.

– The robustness of the whole system (ropes, chain strands, shackles, etc.), which is essential to withstand the enormous stresses and friction that will be generated during a storm.

In this new chapter dedicated to sea anchors, we will cover the following aspects:

– The importance of ship design for the use of a sea anchor.

– Cone-shaped sea anchor. Limitations for wind´s up a storm.

– The use of a storm riding sail at the stern.

– The parachute anchor.

– Mooring the sea anchor on board.

– The Pardey’s deployment method.

– Final considerations.