The Navionics vs SHOM debate trips up almost every visitor to France, because the two are not really competing for the same job. One is a polished commercial chart you steer by. The other is the official national source that French law actually names. Throw Aqua Map into the ring as the value challenger that sits between them, and you have the three options most cruisers weigh. Having run all three across French waters, here is how they truly compare, and why the answer is not to pick one but to understand what each is for.
What each one actually is
Navionics is a commercial cartography product, now owned by Garmin, sold as an app subscription and as plotter chart cards. It is built for usability: clear charts, autorouting, community depth data, slick integration with Garmin instruments.
SHOM is the Service Hydrographique et Oceanographique de la Marine, the French state hydrographic body. It surveys French waters and produces the official charts, in paper, vector ENC and raster GeoTIFF form. When French regulation refers to nautical charts, it means SHOM.
Aqua Map is a third-party app that displays official-source raster and vector charts, including French coverage, with a flexible pricing model that includes one-time purchases rather than only subscriptions.
So the contest is really commercial polish (Navionics) versus official accuracy and legal standing (SHOM) versus flexible value built on official data (Aqua Map).
Price: the easy axis first
Money is where the three diverge most clearly in 2026.
Navionics is subscription-only. The European regional tiers run roughly 49.99 euros a year for a smaller area and around 99.99 euros for the broader Northern Europe coverage. You pay every year, forever, to keep the charts live.
Aqua Map is cheaper and more flexible: regional chart and premium bundles land around 30 to 40 euros a year, and the one-time purchase option means you can own a chart region without an annual bill.
SHOM raster charts are bought per sheet, at around 38.80 euros each. That sounds steep until you realise you only buy the sheets covering your cruising area, and you own them. Cover a focused region and the total can undercut a multi-year Navionics subscription.
Over a five-year horizon the maths flips the obvious answer. Navionics at 100 euros a year is 500 euros. A folio of SHOM sheets for your patch plus an Aqua Map subscription for daily use can come in well under that, while leaving you legally covered.
Accuracy and the French specifics
This is where SHOM pulls ahead, and where it matters most on the rock-strewn coasts.
SHOM charts are the primary survey of French waters. Their depiction of buoyage, drying heights, isolated rocks and the exact French use of the IALA Region A system is the reference. Crucially, SHOM soundings are referenced to the lowest astronomical tide, the same datum the French tide tables and the coefficient are built on, so the chart depth and the tide table speak the same language and add up cleanly.
Navionics and Aqua Map both base their cartography on official sources, so on open water they are accurate enough that I happily steer by them. The gap shows in the tight, rocky pilotage of Brittany, where I cross-check anything marginal against SHOM. For a worked sense of why the datum and the chart source matter on a tidal coast, the broader explainer on electronic vs paper charts in France sets out the legal and tidal framing in full.
The legal question only one of them answers
Here is the part visitors miss. French recreational safety is governed by Division 240, and for semi-offshore navigation (6 to 60 nautical miles from a shelter) it requires you to carry the official nautical charts of the area. For recreational vessels under 24 metres, SHOM's raster GeoTIFF charts are recognised as equivalent to paper and satisfy that requirement on a suitable device.
A Navionics subscription, however good, is a commercial product and not automatically the official chart the regulation names. The same is true of Aqua Map, even though it runs official-source data. The clean position that keeps a boarding officer happy is to carry the SHOM raster charts for your area for compliance, and navigate day-to-day on whatever app you prefer.
In other words, this is not Navionics versus SHOM. It is Navionics or Aqua Map for steering, plus SHOM for the law.
Usability under way
Day to day, in the cockpit, Navionics is the smoothest of the three. The rendering is clean at a glance, the autorouting is quick, and if you run a Garmin plotter the integration is seamless. It is the one I reach for when threading a busy channel.
Aqua Map is close behind and improving fast, with tracks, routes, tides and offline charts all solid. For the price, the gap to Navionics is small and shrinking.
SHOM is not built for live helming. The raster sheets are exactly that, scanned charts, and the experience is functional rather than fluid. You carry it for compliance and accuracy, not for the joy of using it. SHOM's free online data viewer, though, is excellent for armchair planning before a passage.
Offline and connectivity
All three work offline if you preload, which on the French coast is non-negotiable given how the signal drops mid-Channel and across Biscay. Download charts before every leg. If you want to know exactly where you will lose data and how to push it further offshore, my notes on boat internet in France cover the antennas and SIMs that keep the charts updating.
Plotter cards versus apps
One axis people forget is the chartplotter. If you run a fixed plotter at the helm, Navionics sells chart cards that drop into Garmin and compatible units, and that integration with your instruments, wind, depth, AIS, is genuinely valuable in a busy channel. A card is a one-time purchase rather than a yearly app subscription, though updates eventually cost again.
SHOM and Aqua Map live more naturally on tablets and phones than on a dedicated plotter. So the practical pattern for a boat with a plotter is often Navionics cards at the helm for the integrated picture, plus a tablet running SHOM for compliance and a value app for backup. A boat without a plotter skips the cards entirely and runs everything on tablets, which is cheaper and increasingly what younger cruisers do. Neither is wrong; it depends on whether you have wired-in instruments worth feeding.
Updates and corrections
All three need keeping current, and the rules expect it. An out-of-date chart misses changed buoyage, shifted sands and new hazards, and France treats a stale chart as barely a chart at all. Navionics and Aqua Map push updates through their subscriptions, so as long as you keep paying, the charts stay live. SHOM issues corrections you apply to the sheets you own. Before each season, check that every chart source is on a recent edition, because the moment that catches people out is a boarding officer asking when the charts were last updated.
So which should you carry?
My honest setup, and the one I would give a friend cruising France:
- A working app for daily navigation. I lean Aqua Map for value, Navionics if you run Garmin instruments or simply prefer its feel.
- The official SHOM raster charts for your cruising area, loaded on a device, to satisfy Division 240 beyond 6 miles.
- A second device running a different app for redundancy, because phones and tablets fail.
- The SHOM online viewer for planning at the chart table.
The mistake is treating this as a single winner-takes-all choice. Navionics wins on polish, Aqua Map on price, SHOM on accuracy and on being the only one the law recognises. Use the commercial app for the pleasure of navigating and carry SHOM for the moment a gendarme steps aboard, and you get the best of all three. For the full toolkit including weather and discovery, see my rundown of the best navigation apps for French waters, where these three slot into a wider layered setup.
