The night my anchor dragged in the bay below Porquerolles, the thing that woke me was not the boat moving. It was my phone, screaming on the chart table at half past two in the morning. By the time I got on deck we had slid maybe forty metres toward a French charter cat whose crew were sleeping the deep sleep of people who had not set an alarm. Ten more minutes and I would have been fending off in the dark. That app earned its keep in a single night, and it costs less than a round of drinks.
This is a roundup of the phone apps a visiting cruiser actually wants in France, split into the two jobs they do: keeping watch on your anchor, and helping you find and understand the spot in the first place.
The anchor-alarm apps
The job sounds trivial, set a circle, sound an alarm when you leave it, but the good ones do far more and the cheap ones let you down at exactly the wrong moment. Three are worth your attention.
Anchor Pro is the one I run most nights. You drop your anchor position, set the rode length and a swing radius, and it draws your watch circle on the chart. The clever part is that it learns your real swing as the boat moves on the tide and wind, so it does not cry wolf every time you sail around your own anchor. It alarms not just on position but on weak GPS reception and low battery, the two failures that quietly kill a lesser app overnight. You can also leave the phone on the boat and get the alert pushed to a second device, which is the trick for a dinner ashore.
Ankeralarm is the German-built favourite on the cruising forums, clean and reliable, with a generous free tier and a small one-off paid upgrade. SailGrib AA on Android is the full-featured option and it talks to Navionics charts directly, so your drift circle sits over proper detail rather than a bare grid. PredictWind's Anchor Alert ties into their wider ecosystem and pulls in NMEA boat data and a forecast, which suits anyone already paying for PredictWind weather.
Whichever you pick, the setup matters more than the brand. Set the radius to your actual scope, not a hopeful guess. If you have laid 40 metres of chain in five metres of water, your swing radius is the horizontal reach of that rode plus your boat length, not 40 metres flat. Too tight and you will be woken by every wind shift. Too loose and you will hit the boat next door before the phone makes a sound. And keep the phone charged: an anchor alarm on a dying battery is theatre, not safety, which is one more reason a solar and lithium summer cruise setup pays for itself in peace of mind.
The mooring and anchorage apps
Finding the spot is half the game in France, where good anchorages get crowded in August and where the rules change from bay to bay. Two kinds of app help.
The crowdsourced harbour and anchorage guides are the social network of cruising. They show user reviews, photos, holding-ground notes and whether a bay is rolly in a south-westerly, all from people who anchored there last week. For France specifically these are gold, because they flag the local detail no chart carries: which calanque bans overnight stays, where the Posidonia seagrass beds mean you must pick up a buoy rather than drop a hook, which capitainerie answers VHF and which makes you walk to the office. They also list visitor mooring buoys, their cost and how to pay, which saves you circling a field of buoys wondering which are private.
The other kind is your main chart app, which usually carries an anchorage layer and, increasingly, a basic anchor alarm of its own. I would not rely on a chart app's anchor alarm as my only watch, it is a bolt-on rather than the main event, but it is a fine backup. For choosing where to go, the chart detail matters enormously, which is why I treat the navigation apps for French waters and the social anchorage guides as a pair: one for the depths and hazards, one for the human intelligence.
The France-specific traps these apps help you dodge
A few local realities that the right app will warn you about and the wrong one will not.
- Posidonia seagrass. Large stretches of the Cote d'Azur and Corsican coast now ban anchoring over the protected seagrass, with real fines, and the detail of the Posidonia anchoring ban in France is worth reading before you cruise south. The good anchorage apps mark the protected zones and the buoy fields laid as alternatives. Drop your hook in the wrong patch and an ecological warden may have a word, and a bill.
- Buoy fields versus free anchoring. In the national park waters around Port-Cros and the Lavezzi you are often required to take a marked mooring rather than anchor at all. The apps list these, their numbers and their nightly fee, so you arrive knowing whether you can swing free or must pay for a buoy.
- August crowding. The crowdsourced apps show how busy a spot tends to get, which lets you pick the unfashionable bay round the headland instead of fighting for swinging room in the famous one.
- Weather exposure. Reviews tell you a bay is fine in a northerly and a washing machine in a southerly, the kind of local knowledge that turns a bad night into a good one.
How I actually use them together
My phone runs three apps for this. The chart app is open underway for pilotage and the anchorage layer. When I have chosen a likely bay I switch to the crowdsourced guide and read the last dozen reviews for holding, exposure and any rule about buoys or seagrass. Once the hook is down and set, I open Anchor Pro, mark the anchor position, set the swing radius to my real scope, and only then do I pour a drink.
If we are going ashore for dinner I leave the alarm phone aboard on charge and let it push the alert to the phone in my pocket. The whole system costs almost nothing. The anchor-alarm apps are free or a few euros, the anchorage guides have a usable free tier with a modest annual subscription for the full data, and the value of a single night's undisturbed sleep at anchor in a French bay is hard to put a price on.
A practical word on the alarm itself. A phone alarm is only useful if it is loud enough to wake you through a closed cabin door and a tired body, so test the volume before you trust it, and override your phone's silent or do-not-disturb mode for the alarm app. Several skippers I know learned this the wrong way, with a phone that dragged the boat half a cable while sitting politely on mute. Set the alarm tone to something jarring, not a gentle chime, and put the phone somewhere it will be heard, not buried under a cushion in the saloon.
None of this replaces seamanship. Dig the anchor in properly, lay enough scope, and check your swing against the neighbours before you settle. But on a coast as busy and as rule-bound as France's, the right apps turn anchoring from a worry into the best part of the trip. And on the night the holding lets go, you will be very glad your phone is the one that wakes up first.
