Faster, cheaper marine satellite communication is coming to an ocean near you. Sam Fortescue investigations the options for recreational sailors

Marine satellite communication is becoming faster and cheaper thanks to a connectivity revolution which has the potential to bring rapid internet to every spot on the planet, including the high seas.

In fact, banking giant Morgan Stanley estimates that the satellite internet market will mushroom to $412bn by 2040, as rivals such as Inmarsat, SpaceX, OneWeb and
Iridium tussle for market share.

Thousands of new satellites, sleek new user terminals (antennae to you and me), and significantly keener prices will accompany this transformation.

At the same time, a new battery of low-bandwidth marine satellite communication services are coming on stream.

A man wearing a red baseball cap and black glasses sailing a boat with a satellite antenna on the railing for marine satellite communication

Marine satellite communication: Inmarsat’s Sailor satellite antenna is often popular with offshore sailors wanted a stable data connection

They won’t allow you to fire off an email, or even to call home, but they make simple, reliable tracking and system monitoring a cheap reality.

You can send a brief SMS, update your position on a map and allow manufacturers and boatbuilders to diagnose problems before they emerge.

This is all in addition to the slew of devices available for tracking, messaging and sending an SOS already available from a slew of manufacturers, such as the ACR Bivy Stick, Globalstar’s Spot range and Garmin’s InReach.

Marine satellite communication: A question of data

Many offshore sailors will be familiar with the vagaries of using a basic satellite phone on board.

There’s the anxious wait as the modem establishes a data connection and the breath-holding as the tablet downloads GRIB files and emails at sub-dialup speeds.

The airtime plan is like something from the 1980s cellular world, with separate data plans or calltime, all carefully set up to ensure it works.

With a bigger budget it is possible to install a bigger antenna capable of faster data transfer. But costs can quickly spiral into the hundreds or even thousands of US dollars per month.

Marine satellite communication: A woman wearing yellow hi-viz on a phone on the bridge of a ship

Iridium GMDSS sat phones are intended for commercial use. Credit: GMDSS

All that is changing, however, as global players like Inmarsat invest heavily in new satellite constellations and new entrants such as Starlink roll out their services.

New services and cheaper terminals are already encouraging more offshore sailors to invest in marine satellite communication, according to Iridium.

‘Fifteen years ago there was no way most people could afford to have satellite comms on board,’ says maritime director Dan Rooney. ‘But consumers are seeing that the equipment size, performance and price are accessible. We’ve expanded significantly into broadband services. We anticipate a very large growth in leisure for mid-band – in the small, white boat market.’

Iridium recently completed the successful launch of 66 new LEO (Low Earth Orbit) satellites to boost its data services from pole to pole.

It is the backbone behind its new Certus service, which offers speeds from 22kbps (Certus 20) up to 704kbps (Certus 700).

The control room of Immarsat, full of screens

Immarsat satellite orbit control room at head office in London. Credit: Duncan Soar

The most popular for the sailing market is proving to be the Certus 100, which you can buy from MailASail for £2,499+VAT.

It has a small solid-state antenna for rail-mounting and a slim black box modem that goes below decks.

Power consumption is minimal and airtime is efficiently priced, from $97 (£84) per month for 10MB of data.

Market veteran Inmarsat is also busy investing in LEO capability, with plans to launch some 180 satellites in the coming years. It has also launched the first of two new I-6 geostationary satellites, aimed at doubling network capacity under the codename Elera.

This can offer speeds up to 1.6Mbps, but is geared at enabling small packets of data to support the Internet of Things.

A satellite dome

Inmarsat’s FleetOne satellite domes are still the preserve of superyachts with big budgets

There are key benefits for sailors.

‘Elera will bring smaller terminals, lower power consumption but on the same basis of global connectivity and flexible price plans, because we know there are seasonal requirements and voyage-based requirements,’ says senior VP Peter Broadhurst. ‘That will lower the cost and open up lots of possibilities for the leisure sector.’

Installing Elera requires just a solid-state antenna the size of an epirb, then a small black box below deck.

Where the current FleetOne system costs around $3,500, Elera should ‘cut that in half’, according to Broadhurst. After that, you’ll pay according to the data you use.

At present, $119/month buys you 10 minutes of calls and 15MB of data.

Making marine satellite communication cheaper

Rather than obsessing about the cost of airtime, you should focus on using it efficiently, according to offshore comms specialist Ed Wildgoose of MailASail.

‘Compression software will give you perhaps a 2-5 times cost saving, correct firewalling can give you a 5-20 times cost saving, and just being shown how to use the equipment correctly and optimally is often a 2-5 times cost saving. All of those stack on top of each other and add up.’

He gives the example of a Las Palmas customer who was used to paying around $8 to send one email over satellite using the laptop.

‘I reconfigured things to use our compression software, firewalling etc, and resent a bunch of larger emails, then checked the cost. It was 10 cents or so.’

marine satellite communication: A router for satellite data on a boat

MailASail’s Red Box Pro Ultra router streamlines your satellite data usage

Wildgoose has built his own device to achieve all these things, combining satellite with marina WiFi reception and super-fast 4G+. It’s called the RedBox, and has just been given a massive technical upgrade.

But neither Rooney at Iridium, nor Wildgoose at MailASail believe that we’re going to achieve terrestrial-grade communications for boats via satellite.

‘To me, when you go sailing, you do so to get away from it all, not to take it all with you,’ says Rooney. ‘You want a bit of social media, a bit of telemetry, then safety stuff such to keep yourself secure.’

There are also insurmountable technical limitations, he adds. ‘Latency is higher and bandwidth is limited, so the overall experience of broadband by satellite is very, very different. That shapes a user’s behaviour to only put over the air what needs to go. You wouldn’t stream Netflix, for example.’

marine Satellite communication - a satellite dome for a boat

Marine satellite communication: Inmarsat’s FleetOne satellite domes offer large amounts of data at high speeds. Credit: Stuart Pearce

Well, you and I might not, but a guest on a superyacht certainly would. Just not with Iridium’s satellite constellation.

For the fastest connection, you need to connect to Inmarsat’s Ka-band satellites. Here there are packages that give you speeds up to 150Mbps – at a price to match.

So-called V-Sat terminals are huge and power hungry, but can basically focus a satellite’s entire beam on a given vessel to zap huge amounts of data back and forth.

This is the stuff of oligarchs, however. Most of us operate at the other end of the spectrum.

And at the narrow end of the pipeline, bandwidth is measured in simple bits – no hint of a ‘mega’ prefix. It’s not enough to send voicemail, but it works for SMS and, crucially, for tracking and the internet.

Continues below…

Sweating the small stuff

This is the domain of operators such as the UK Lacuna and US-based Swarm –now snapped up by SpaceX. Lacuna uses an emerging low-bandwidth protocol called LoRaWAN – Long-Range Wide Area Network.

Its effectiveness has already been demonstrated for remote boat monitoring, where it is used by Germany’s BoatOfficer and New Zealand’s BoatSecure with a range of up to 50km from a land-based router.

But there’s no limit in space, and a LoRaWAN signal has already been bounced off the moon successfully. Lacuna’s satellites orbit at 500km altitude.

There are six in place, with funding to increase that to 30, with distant plans for 240. That means that there is not always a satellite in view.

A rocket taking off with white and orange smoke carrying satellites

OneWeb has launched 648 satellites to date

‘You have to wait for the satellite to be overhead, so it’s not really suited to time-critical situations,’ says chief commercial officer Jon Pearce. ‘But if you had a bilge pump that failed and your boat was filling up, it would alert you.’

The kit needed to receive and transmit using Lacuna costs a fraction of the higher bandwidth services. You just need a Lorawan sensor costing £200 and a subscription.

Running costs depend on how many 50-byte transmissions you want to send.

The voice and SMS services from Globalstar are a step up the bandwidth ladder. Coverage here is not global, although the sailors in the Mediterranean and Atlantic shouldn’t have connection issues.

The Indian Ocean, Pacific and high latitudes are another matter. Thuraya really only covers the Med plus a few hundred miles off the European and Asian coasts.

Stuff of dreams

The sharp end of the business is in what’s known as Low Earth Orbit (LEO) satellites, which race around the planet between 550km and 1,500km up.

This is where OneWeb, Starlink and China’s GalaxySpace are investing in constellations of tens of thousands of small satellites.

Their job will be to beam blanket internet access down to the planet below. Elon Musk’s baby, Starlink, is the perhaps most talked about.

A satellite revolving around the earth

According to OneWeb, all of its satellites will deliver an impressive 7.2Gbps

His launch company SpaceX has already delivered some 1,350 shoe-box sized satellites into low-earth orbit and he has plans for a further 3,000 by 2024.

In the end, Starlink hopes to launch an astonishing 42,000 satellites for total saturation. Download speeds of up to 110Mbps are already possible in some areas.

GalaxySpace aims to provide 5G download speeds by satellite – up to 500Mbps. And OneWeb, which is part-owned by the British government, has managed
400Mbps in tests.

This would be a gamechanger if it were possible to roll out more widely. You could run a business empire from the high seas if you wanted, stream movies, have Zoom-call lessons for the kids and still have plenty of bandwidth left over. Whether you’d manage to fit in any sailing is another matter.

Beaming super speed internet across the Earth’s surface is all well and good, but users will need to be able to receive the signal.

With existing satellite systems, that requires either a small stubby antenna for low bandwidth signals or large domes mounted aft on a pole or on the spreaders.  The latter are often known as ‘eggs’.

A sailor wearing a baseball cat looking at weather data on a computer screen while sailing

Marine satellite communication: Garmin’s InReach devices include weather information that can be used for routing ocean passages. Credit: Tor Johnson

OneWeb has put thought into the marine sector. Its marinised parabolic antennas measure 69cm in diameter and weigh 22kg, encased in a plastic dome.

This is identical to the Fleet Broadband 500 antenna built for Inmarsat users.

The difference is in the capabilities. ‘OneWeb’s LEO network will have a total usable capacity of more than 1.1Tbps,’ says Ben Griffith, VP Mobility at OneWeb. ‘Each of our 648 satellites will deliver an incredible 7.2 Gbps – delivering hundreds of Mbps.’

Good if it works out. After 13 launches, OneWeb has put 428 of its planned array of 648 satellites into orbit, but coverage is currently limited to north of the 50th parallel. We won’t know what is on offer to sailors until full coverage rolls out late this year and next.

There is no pricing information yet, making it hard to assess whether it is viable for leisure sailors.

A woman wearing sunglasses and a tshirt holding a black sat phone on a boat

Using a satellite phone for voice calls while on passage can be invaluable for things like seeking medical attention. Credit: Tor Johnson

Starlink has invested more money into launches and has a ‘beta’ service operating onshore already.

Its dish and black box router will set you back £529, with a further £89/month for unlimited downloads – expensive for terrestrial but unheard of for marine.

It is thought that the costs of building the kit are about twice that, meaning that Starlink loses money on every order at the moment.

Expect the front-end prices to increase in the future as the system gains traction.

A GRIB file showing weather information

GRIB files are a data-efficient way of receiving detailed forecasts and are viewed via dedicated apps

The problem with StarLink is that its dishes are motorised and heated in order to keep snow and ice at bay and is therefore totally unsuitable for use on small boats in a corrosive marine environment.

The company did not respond to enquiries about a marinised user terminal, suggesting a longer wait for sailors.

GalaxySpace is Chinese state-owned and therefore remains something of an enigma for the time being.

So what does all this mean if you’re cruising off-piste? Well, you still need to sit down and work out what you actually want to do with your marine satellite connection.

Where on the spectrum between big data and the bare minimum do you sit? Smaller, cheaper terminals with a more robust connection promise to improve the experience of using satellite communications.

The running costs should also come down thanks to stronger competition in the middle ground, which is where most boat owners are likely to sit.

And if Musk et al’s ambitious plans bear fruit then there is the prospect of a huge step up in performance for a fraction of the current cost. Watch this space!

What is latency?

In a nutshell, latency is the delay on the line when sending a radio signal – whether voice or data.

In satellite comms, it is mostly due to the large distances the signal must travel to reach a distant satellite and bounce back down to a terrestrial base station.

It is a particular problem with voice calls (or videoconferencing), where a long wait for audio to reach you can paralyse a conversation.

Low-Earth orbit (LEO) satellites might have a latency of 40 milliseconds (ms) – barely noticeable.

Mid-Earth orbit (MEO) satellites are up to 12,000km from Earth, entailing a latency of up to 24ms.

The furthest out are geostationary satellites – at around 35,000km – where delays for a round-trip signal can reach 800ms.

Sometimes, signals are routed via multiple LEO satellites, increasing the delay. Routers, switches and other hardware can also add latency.

What are MBPS?

Speed, in a word. While file sizes are measured in kilobytes (KB), megabytes (MB) or gigabytes (GB), transfer speeds are measured in bits per second.

Eight bits (b) contain enough to form a single letter, like ‘g’ and make up one byte (B). 1,024 bytes make up 1KB, and 1MB is 1,024KB (or 1,048,576 bytes) – enough data for a medium-sized novel.

So a connection rated at 8 megabits per second (8 Mbps) can transfer 1 megabyte (1MB) per second.

The question is, how fast do you need your satellite connection to be?

The answer depends entirely on what you need it for.

Marine satellite communication: Globalstar's Spot X offers entry-level sat comms

Marine satellite communication: Globalstar’s Spot X offers entry-level sat comms

If you just require emergency calls and the occasional reassuring SMS message, then you can make do with a relatively narrow ‘pipe’ – as low as 2.4Kbps, depending on call quality and the equipment you’re using.

You won’t see this number, though, because you will be buying bundles of minutes and texts.

For sending and receiving simple emails, it is slow work on these voice data rates.

The average email is around 59KB in size, so you’d want something faster – such as the new Certus 20 from Iridium, which offers 22Kbps. Photos and web browsing consume much more data.

A photo can easily amount to 1MB, and websites are often image heavy too, for which you will need a data connection of some 100Kbps or higher.

Video calls need at least 350Kbps – ideally much more.

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