How to dry out to at any anchorage (and harbour)

Ken Endean describes how standing your boat on its own two (or three) feet can open up a whole host of anchorages and harbours otherwise out of reach

Almost all vessels, in the days of working sail, had to take the ground when calling at destinations around Britain. Some port towns were on estuaries that dried out at low tide; many coastal harbours had walls that did not extend beyond low water, because underwater masonry was disproportionately expensive.

Until the Industrial Revolution brought steam dredgers, and also machinery for construction of gated basins, taking the ground was the norm rather than the exception for both coastal craft and ocean-going ships. At some places, small traders were even run onto open beaches, where their cargoes could be unloaded directly into horse-drawn carts.

Their skippers did that kind of thing regularly, and modern, amateur mariners must make similar judgments about the effects of wind, waves, and tides when beaching their boats. For marina-based sailors, these might seem like non-essential skills, divorced from the everyday world of pontoons and digital navigation, but that would be to ignore the safety aspect.

When a storm is threatened, the normal reaction is to seek a sheltered mooring, but in some places there may be no suitable deep-water berths, or those that are available might be seriously exposed. Visitor moorings are often in the positions that the locals do not favour, just beyond the best protection.

A prudent visitor is likely to look for better shelter in an alternative bay, inlet, or creek. If this involves using anchors and parking their boat on the sand at low tide, then that is a small price to pay for comfort and security.

Even in the absence of storms, a yacht that is designed or equipped to sit on the bottom gives her crew a wider choice of cruising destinations.

For instance, most of the harbours and inlets on Britain’s eastern flank, and the north coast of Cornwall and Devon, are fascinating places to visit by sea but dry at low tide. In good weather, a boat that can stand on her own feet will enable her crew to explore them properly, rather than merely sail on past, heading for the next big harbour.

Fin keels

For taking the ground, a yacht’s most important feature is her underwater arrangement, and principally her keel(s). To remain upright, a single fin-keeler requires beaching legs, complete with rope stays to resist fore-and-aft swing and possibly spacer brackets near the waterline to prevent lateral movement.

A yacht on legs may appear dangerously top-heavy but is generally more stable than she looks because about a third of her weight is at the bottom of the keel. French sailors use legs enthusiastically but mostly on firm Brittany sand. On softer foreshores there is more risk of the keel/legs combination settling to one side, and therefore it is important to check, before grounding, that the bed below the boat has no transverse slope.

Lifting keels

A centreplate in a stub keel will keep the hull closer to the bed, but there is a chance of the plate jamming if its case becomes packed with mud or gravel. There should be some means of clearing such material and flexible sealing strips along the keel slot to reduce the risk of ingress.

Maintenance might require the plate to be dropped out or lowered, and some American designs minimise corrosion by having plates of bronze or stainless steel. Some cruisers have internal ballast, drop plates, and no stub keel; their hull sits on the bed and needs a hull shell strong enough to bear on stones without damage.

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A ballasted lifting keel could be an ideal compromise, but a lot depends on its durability and its lifting machinery. Repairs and servicing can entail lifting the yacht in order to drop out the heavy keel, and that could become an expensive habit.

Bilge keels

Twin keels and bilge keels ‘democratised’ British coastal cruising by enabling economical owners to use drying estuary moorings before marinas proliferated. In design reviews they are often treated as a second-best option, and a typical boat test is usually carried out on a fin-keeled version.

Any advantages of fin keels are reversed in unsophisticated cruising grounds, because the twin or bilge-keeler can be parked almost anywhere and visit any harbour or anchorage. A small drawback of twin keels is revealed if one of them is positioned over a hole or soft spot left by a previous visitor, whereupon the yacht could heel sharply while she settles.

A bilge-keeler, with a heavy central keel and two small, unballasted bilge plates, might then remain slightly more level.

Twin rudders

Twin rudders have become popular for wide-sterned yachts, so that one should remain immersed when heeling lifts the other out of the water. When aground, they can perform another function by providing three-point stability in conjunction with a single keel, but only on boats where they have been designed and built to do so.

They will be strong enough to resist high lateral loads while sailing, but the additional vertical forces through the blade, post, tube, and supporting structure will need to be accounted for in the building, as well as reinforced shoes to withstand contact with the ground.

Multihulls are very well suited to taking the ground. Being unballasted, they normally rest on top of soft foreshores rather than sinking in, and are unlikely to heel over significantly on uneven surfaces. If they are lightweight craft, with daggerboards rather than stub keels, they do not touch down until the water is very shallow, when any waves are likely to be breaking further offshore, reducing the risk of grounding impacts.

Stern gear, such as propellers below the hull, may be vulnerable to damage on a boat that is designed to sit on its belly. Some motorcruisers are potentially vulnerable. The props should be protected by guards or grounding skegs, likewise the rudders unless they can be hinged up.

Know your seabed

In good weather or bad, a crew could take their cruiser up an estuary to visit a waterside settlement or perhaps to seek shelter in the lee of thick woods.

On most British estuaries, the bed is likely to be muddy, although where the low-water channel weaves across a wide reach it may have scoured away the mud to leave sand and shingle, which will be much more popular with anyone who wants to walk on the bed at low tide.

Anchoring a yacht close to small boats on drying moorings can cause a problem because all craft will take the ground while lying to the ebb. On the flood, the locals, if of shallower draught, will lift off first and might then swing into the yacht. It’s best to anchor well clear of moorings if possible.

At inland locations there is always a chance of finding rubble or debris on the river bed, particularly where there were industrial sites such as brickworks or quarries. The best large-scale charts are likely to show obstructions such as old wrecks, where derelict boats and barges were left to rot.

If the water is muddy, it will be difficult to inspect the bed on arrival, but before the yacht touches down a check might be made by paddling the tender around it and probing with a long boathook. When the bed uncovers, it’s time to take a better look around and decide whether to move or stay put.

A coastal drying anchorage is likely to be a bed of clean sand or shingle, possibly between outcrops of rock, and here again the largest-scale charts are valuable, to indicate the limits of the rock. For the UK, that means Admiralty charts and for Brittany the foreshore areas on French SHOM charts have particularly clear ‘artwork’.

On the French coast and islands, watch out for ‘bouchots’ which are dangerous rows of old posts for shellfish farming, generally of iron and about 2 metres high. There may also be lines of stones or boulders that are the remains of old fish traps or other structures. For low tide exploration and climbing down onto the sand, carry a decent boarding ladder – one that extends well below the waterline.

Ground Tackle

Anchoring on a drying seabed is no different from anchoring anywhere else, but there is one clear benefit, particularly on a sand/shingle bed when strong winds are anticipated.

At the first low water after arrival, the position of the anchor can be checked, perhaps by pacing out the yacht’s swinging circle to ensure that there should be no clash with rocks or neighboring boats. The anchor can then be dug in, to maximize its holding capacity.

A kedge can be useful in three ways. On an estuary, when a yacht lifts off with the flood tide, she will initially be inclined to float slowly upstream, sliding across the bottom, and may override her anchor chain so that it becomes wrapped around her keel(s) or other appendages.

This can be avoided by anchoring fore-and-aft, and that technique could also be used to keep her within a limited space. If an obstruction such as a small rock lies within the yacht’s swinging circle, the kedge can be laid out as a wing anchor to limit the swing.

Some owners like to beach their yachts close to the high-water mark, bows inshore, with a kedge laid out astern to prevent the boat swinging until it is used to haul off for departure. On sand or mud, many modern anchors will give satisfactory holding, but weed will blanket an anchor fluke and growing weed is often on rocks, which could be treacherous for holding and damage.

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The post How to dry out to at any anchorage (and harbour) appeared first on Yachting Monthly.