Ten years ago, the question of onboard internet had an easy answer: you didn't have any, or you paid an obscene amount per megabyte over Iridium. Today the balance has shifted. 4G routers cover most of the European coast reliably, and low-earth-orbit satellite systems (Starlink chief among them) put broadband within reach of boats that would previously have been offline for days. The interesting question is no longer "can I get connected", but "which link fits this boat, this cruising area and this power budget". Below is how to think about it as an owner, not as a shopper.

What "reliable" actually means afloat

Reliability on land means uptime. On a boat it means something more specific : the link must hold in motion, tolerate spray and salt, survive on a 12 or 24 V bus, and stay up when the boat heels or the antenna is momentarily obstructed by the mast. It also means predictable behaviour when the boat crosses a border or leaves cellular range. A router that drops silently is worse than no router at all, because the crew assumes messages have been sent.

Two numbers matter more than raw speed :

  • Latency. For weather routing, VoIP or a live dashboard, 60 ms feels natural, 600 ms is painful, 1500 ms is unusable.
  • Consistency. A 20 Mbps link that drops to zero every four minutes is worse than a steady 3 Mbps link that never blinks.

Speed only matters once those two are handled. Very few use cases on a cruising boat actually need more than 5 Mbps down.

4G/LTE : the coastal workhorse

Along the European coast, a well-installed 4G router remains the single most cost-effective link. Coverage typically extends 15 to 30 nautical miles offshore from populated coasts, with dead zones behind cliffs, in some fjords and in the middle of larger bays where cell towers are aimed inland. In the Med, coverage is often usable well past 20 NM ; on Atlantic passages it drops off faster because towers are further apart.

What actually makes a marine 4G install work :

  • An external MIMO antenna, mounted high and clear of standing rigging. Two antenna ports on the router, two cables, two antenna elements. Internal antennas inside a saloon are a waste of money on a boat with a metal or carbon structure.
  • A cat 6 or cat 12 modem. Cat 4 is fine in town, but the aggregation from higher categories is what pulls a usable signal out of a distant tower.
  • A multi-operator SIM, or at least dual SIM. A single French operator will let you down the moment you cross to Spain or Italy, even with roaming, because handover between carriers at sea is often slow.
  • DC-native power. Anything you run through an inverter is a future problem. A router that accepts 9 to 30 V directly will draw between 5 and 15 W in normal use.

4G is also where you get the best value on telemetry. The Oria Box uses 4G with an included multi-operator SIM because for reading the NMEA 2000 bus, pushing engine hours, positions and alerts, the payload is tiny and the coverage envelope matches where most owners actually sail. If you want the wiring context for feeding a router or a telemetry unit off the boat's network, see our guide to NMEA 2000 wiring and sensor expansion.

Starlink changed the offshore picture. On a passage 80 NM off the coast, where 4G is a memory, a properly powered dish will hold a broadband link with latency in the 40 to 80 ms range. That is the same order of magnitude as a home fibre connection. For a delivery skipper wanting live GRIB updates, a charter operator sending invoices from anchor, or a family keeping kids happy on a two-week cruise, it removes a real friction point.

The trade-offs are honest and worth stating :

  • Power. The flat "high performance" dish typically draws 50 to 75 W continuously, spiking higher in cold weather when the heater kicks in. Over 24 hours that is 1.2 to 1.8 kWh, which on a 12 V bank is 100 to 150 Ah per day just for the internet. Plan solar and battery accordingly. Our overview of onboard energy, batteries and solar is a good starting point if you have not already sized the bank.
  • Mounting. The dish needs a clear view of the sky. On a sailboat, mast, boom and sails will cause momentary dropouts as the boat heels or tacks. Most owners live with it. Aft arch installs on motorboats behave far better.
  • Plans. The "Roam" tier works globally but has caveats on ocean coverage. The "Mobile Priority" (maritime) plan works well offshore but costs several times more per month. Read the current terms before assuming your plan works where you sail.
  • Latency during a rain squall can degrade, and heavy motion in a seaway will produce brief dropouts. It is not a synchronous, guaranteed link.

Where Starlink is genuinely superior : offshore passages, remote anchorages, and any use case that involves video calls, cloud sync or streaming. Where it is overkill : a boat that never leaves coastal waters and needs the connection mainly for weather, messaging and telemetry.

Satellite messengers still matter

Neither 4G nor Starlink replaces a proper safety-grade satellite communicator. If the dish goes down (physical damage, blocked view, power failure) and you are 200 NM offshore, you still need a way to send a position and a distress message. A handheld Iridium unit or an inReach lives on batteries, fits in a grab bag, and does not care about your electrical system. Treat it as a separate layer, not a backup for the same job. We covered the options in detail in our piece on satellite communicators for offshore sailing.

The mental model : Starlink and 4G are for comfort, productivity and data. A messenger is for safety. Do not merge the budgets.

Combining both : failover on real boats

The interesting setups today are hybrid. A dual-WAN router picks the best available link automatically : 4G near the coast, Starlink further out, and the ability to bond both when neither alone is enough. What to look for :

  1. Automatic failover in under 30 seconds, not manual switching.
  2. Per-device routing rules. You want your chartplotter's weather download to prefer 4G (cheap) and your video call to prefer Starlink (fast). A good router does this on its own.
  3. A dedicated telemetry path that never touches the main WAN. Your monitoring, geofencing and anti-theft alerts should keep working even if the crew's Netflix session has saturated the pipe. The Oria Box uses its own SIM precisely to stay independent of whatever router the owner installs later.
  4. Sensible traffic shaping. Bandwidth caps per device, per SSID, and blocked auto-updates during passages.

For a charter operator, this becomes a business question, not a comfort one. Guests expect coastal Wi-Fi. A fleet-wide policy of 4G with a Starlink option on longer-range boats tends to strike the right balance ; see our notes on choosing motorboats for a charter fleet for how connectivity fits into the operating cost picture.

Picking what fits your boat

A few honest scenarios :

  • Coastal cruiser, weekends and two-week summer trips, Med or Channel. A good 4G router with an external antenna covers 95 % of your needs. Add a satellite messenger for safety. Skip Starlink until you actually need it.
  • Serious cruiser doing Biscay, Corsica, Baleares, or offshore hops. Add Starlink to the 4G setup. Size your batteries and solar for the draw. If you're planning a longer passage, our guide to crossing to Corsica is a realistic example of where connectivity actually matters underway.
  • Liveaboard or long-distance cruiser. Starlink is now the norm rather than the exception. A 4G router still earns its place as a cheap secondary link in port. Redundancy is not optional.
  • Charter fleet operator. 4G for telemetry and guest Wi-Fi on coastal boats, dual-WAN with Starlink on boats that leave the sight of land. Monitor data usage per boat and per week.

Whatever you pick, the boat comes first : an antenna installed badly will underperform any hardware, and a router run through a shore-power inverter will fail during the first serious passage. Treat the internet link like any other onboard system : DC-powered, mounted properly, and sized to the actual use.

Once the pipe is reliable, the interesting question becomes what to send through it. Position tracking, engine hours, geofence alerts, an anti-theft ping the moment someone touches the ignition without your knowledge : these are all tiny payloads that the Oria Box handles over 4G, which is why the platform stays useful even on boats without a satellite dish. What would you actually put on the wire, if the wire never dropped ?