My boat draws 2.1 metres, which on the French Atlantic is a permanent calculation and on the Mediterranean is a non-event. After two seasons working both coasts I have stopped reading anchorage guides written for shoal-draft boats, because half the pretty bays they list dry out or carry barely a metre at low-water springs. What a deep keel needs is different: somewhere the water stays under you all night, the holding takes a heavy anchor, and the swing room does not put you on a rock you cannot see. Here is where I have found that, coast by coast.
Why draft changes the whole game
A boat drawing 1.4 metres can creep into the back of a Breton creek, sit on the mud at low water and float off on the flood. Mine cannot. On the Atlantic, where spring ranges run between 6 and 10 metres, a sounding of 4 metres at high water can mean drying ground six hours later. So my rule on the tidal coasts is brutal and simple: I only ever read the chart as the depth at the next low water, and I want at least my draft plus a metre under the keel at that moment, before I even think about the night's wind.
The Mediterranean inverts the problem. Tide there is a footnote, often under 30 centimetres, so the depth you sound is more or less the depth you keep. The constraint on the Med is not the bottom dropping away, it is the bottom dropping away too fast. Many Riviera bays shelve from 3 metres to 30 metres in a boat-length, and the protected Posidonia seagrass forces you to drop on small sandy patches. A deep-draft boat actually has an easier time here than a shoal one, because the deep water sits close in.
Mediterranean: deep water that comes to you
The Med is where a heavy keel feels least restricted. At Porquerolles and the Hyeres islands the south coast bays carry serious depth right up to the rocks. Plage Notre-Dame on Porquerolles, often called one of the finest beaches in Europe, lets you anchor in 3 to 6 metres over fine sand, and a deeper boat simply lies a little further out where the bottom is still good holding. The trick is to aim the keel at a pale sand patch and watch the chain go down through the clear water, which on a calm day you can do by eye from the bow.
Around Port-Cros, the national park has laid 68 ecological mooring buoys precisely because anchoring is so restricted, and 5 of those buoys are reserved for boats between 15 and 30 metres. If your boat is big as well as deep, those buoys solve the holding and the seagrass problem in one move. Anchoring is banned outright in the park's marine heart for any vessel over 30 metres.
The Rade de Villefranche-sur-Mer is the textbook deep-draft anchorage of the eastern Riviera. The bay averages 17 metres deep and falls to 95 metres in the middle, so the question is never whether you will float, it is whether your chain reaches the bottom on the shelf. Anchor on the sandy edges in 7 to 10 metres, well clear of the seagrass, and you have a holiday-postcard anchorage that takes any keel. Before you drop anywhere on this coast, read up on the Posidonia anchoring ban in France, because dropping on the dark grass is now an expensive mistake as well as a destructive one.
Atlantic: deep keels and big tides
The Atlantic is where draft earns its respect. The good news is that the same big tides that punish you also carve genuinely deep anchorages.
The Glenan archipelago, about 10 miles off Concarneau, is the standout. The central anchorage, La Chambre, sits between Saint-Nicolas, Bananec and Cigogne islands and holds boats in white maerl sand that gives excellent grip. There is enough water through most of the basin for a 2-metre draft to lie afloat at low water if you pick your spot off the drying banks, and the pilotage among the rocks is the real test, not the depth. I went in on a rising tide my first time and crept out the same way, which is the only sensible way to learn it.
Belle-Ile, Houat and the Quiberon bay islands give you sandy-bottomed bays that suit a heavy anchor. Ster-Vraz on the wild west side of Belle-Ile is a natural harbour with a mainly sandy bottom, well protected from south, east and north-east winds, where boats lie overnight to dodge the swell. It is exposed to anything from the west, so it is a fair-weather hole, but in the right forecast a deep keel sits there comfortably. Off Houat, the great 2.2-kilometre arc of Treac'h er Goured beach shelves into clean sand and gives plenty of swinging room.
A word on holding tackle, because deep water only helps if the anchor stays put. On the Atlantic I run at least four times the high-water depth in scope, which in a 10-metre anchorage means 40-plus metres of chain, and I set hard astern every time. If you are weighing the whole anchor-versus-marina question on cost, the cost of anchoring versus a marina in France is worth reading, because a deep boat in a deep anchorage often saves the most: the bays that suit you are exactly the ones the shoal-draft crowd cannot use, so they are emptier.
Corsica and the wildcards
If you push on to Corsica, the deep-draft cruiser is spoiled. The island's bays often carry serious depth right up to the shore, with sand and Posidonia in roughly the same pattern as the mainland Med, so the same discipline applies: drop on sand, keep off the grass. The advantage of a heavy keel here is that the popular bays shelve fast, and where a shoal boat tucks into the crowded shallow corner, a deep boat can lie in clean water just outside it with better swinging room and a quieter night. The trade is exposure, because the deeper water is usually the more open water, so I watch the forecast harder in Corsica than almost anywhere.
Back on the mainland, two wildcards are worth knowing. The Lerins off Cannes carry a useful patch of deep water on the channel between Sainte-Marguerite and Saint-Honorat, the latter a monastery island 1.6 kilometres off Cannes whose monks still work an 8-hectare vineyard. And the Rade de Toulon and the gulf of Hyeres hold deep anchorages that a 2-metre keel uses without a thought, the depth being a non-issue and the wind the only real variable.
Reading a chart for a deep keel
The discipline that keeps a deep boat off the bottom is dull and unglamorous, and it is the whole job. I do three things at every anchorage. First, I find the lowest astronomical tide depth on the chart for the swinging circle, not the depth where the anchor lands. Second, I check the tidal coefficient for the night, because a French spring with a coefficient near 110 drops the water far further than a neap near 40. Third, I plot my swing: a deep keel that touches at low water on the wrong heading is no better off than a shoal one that grounds on purpose.
In the Med, the equivalent discipline is the seagrass and the shelf. Use the free DONIA app to find sand, drop precisely, and do not let the boat drag back over a meadow in the afternoon sea breeze, which on the Iles d'Hyeres can build to Force 5 or 6 by mid-afternoon even when the morning was glassy.
The deep-draft shortlist
If I had one season and a 2-metre keel, I would point the bow at the Glenan for the Atlantic and Villefranche or Porquerolles for the Med. They are the four anchorages where I have never once worried about the bottom, only about the wind and, on the Med, the grass. A heavy keel is a liability in a drying creek and an asset in deep clear water, so play to it: skip the shallow bays the brochures love, and go where the water is honest all the way to the rocks.
