How we solved our internet access

Connection to the internet was one of the things we wanted to work smoothly while we sail around the world. So before we left Sweden, I thought a bit about how we would have access to the internet while we live on the boat and sail from country to country, crossing an ocean or while in a marina or at a remote bay. This post is about how our preparations matched reality.

Tech stuff

I start with a review of some concepts and technology regarding connecting to the internet.

Amount of data

In most services for connecting to the internet, it is possible to select different amounts of data per month. The more data the higher the cost. Sometimes there is also the possibility of an unlimited amount of data. Most services count how much data is transferred between the internet and your device, ie also upload to the internet. This is how mobile services calculate your data usage.

Data usage is stated in the number of Bytes (characters) per time period (eg month).

  • GB = Giga Byte, billion bytes
  • MB = Mega Byte, million bytes
  • kB = Kilo Byte, thousand bytes

Some services charge for transmission time used instead of data volume, eg satellite connections work that way.


How fast information is transferred between the internet and your computer. Units according to the table

MB/secmillion bytes per second
kB/secthousand bytes per second
kbits/secthousand bits per secon
Byte = character or digit = 10 bits

Technology, coverage and bandwidth

It is possible to access the internet via various technical solutions and on a boat, it is possible to utilize WiFi, mobile network, satellite, or SSB radio with a modem. Within these four basic technologies, there are different generations of equipment where a younger generation has better transmission capacity than the previous one. The table below gives an approximate idea of the range and bandwidth of the different technologies that are relevant for a boat.

Connection typeCoverageBandwidth
Wifi100 mDepends on the internet connection from the WiFi-network and the number of users on the WiFi-net.
The range can be extended, but then a so-called directional antenna is usually required and it only works when the boat is at a jetty.
A WiFI-net is capable to transfer up to 50 MB/sec, so the limitation is almost always the connection to the internet
Mobile 4G LTE10 km< 15 MB/sec depending on the signal strength and 4G technology
Mobile 3G15 km< 4.2 MB/sec depending on the signal strength and 3G technology
Mobile 2G20 km< 0.03 MB/sec depending on the signal strength and 2G technology
Satellite Inmarsat
Fleet Broadband 500
Global< 50 kB/sec depending on signal strength
Satellite Inmarsat
Fleet Broadband 150
Global< 15 kB/sec depending on signal strength
Satellite IridiumGoGlobal< 0.25 kB/sec depending on signal strength
SSB-Radio + Pactor 4 modemGlobal< 0.9 kB/sec depending on signal strength
Data rates radio communication technologies

For example, IridiumGo is very slow compared to a 4G which is about 10,000 times faster than IridiumGo. A GRIB file that is 2 MB in size takes about 2 seconds to download with 4G. With IridiumGo it will take about 20,000 seconds (5.5 hours) to download the same GRIB file.

IridiumGo is very sensitive to signal strength. There are 5 bars that show signal strength and at 4 bars the bandwidth has been reduced by half and at 3 bars the bandwidth is only 10%.

WiFi technology

To connect to the internet via WiFi network, there are basically two different ways. If you get a WiFi router, make sure that it can handle both login methods. and the variations of those.

  • WiFi login
    The Wifi network requires login. Everyone who connects can use the same password and it is possible to log in with the password until the owner of the WiFi network changes the password. This is a common solution for smaller WiFi networks in cafes and bars.
  • Web login
    When connecting to the WiFi network, a web page opens that requires you to log in. It is only possible to connect one computer or a few computers at a time with the login information. There is always a limit to how long you can use the login, eg 1 week from the first login. This is a common solution for larger WiFi networks in marinas and hotels.

Mobile technology

There are several different types of mobile networks in operation today, 2G, 3G, and 4G. The term comes from the type of communication technology used. For us as users, it basically means faster and faster internet connection for each new generation.

  • Our Swedish SIM cards can be used in other EU countries up to 4 months after leaving Sweden. After that, the operator has the right to charge other prices or you can choose to turn off the SIM card.
  • In addition to local SIM cards, there are also international SIM cards. These are SIM cards that are valid in many countries around the world. The disadvantage of them is that they usually have a higher cost than local SIM cards and that they are only sold in certain countries.
  • There are phones that can have dual SIM cards and the next time we buy a new phone, we will get one. Then you can have your regular SIM card and a local SIM card at the same time and choose which SIM card is used.
  • Newer mobiles support so-called e-SIM card and this means that you can download the SIM card online (no physical SIM card is needed to be inserted into the phone).

Mobile devices

What equipment is needed to connect to the Internet via a mobile network?

  • Mobile router with external antenna for best range
    This solution requires a separate SIM card for the mobile router and if you want internet when you are ashore, you need to get a SIM card for your phone as well.
  • Or use your phone and share the connection via the phone’s WiFi hotspot.

Global internet technologies

In areas where there is no coverage from mobile networks, connection to the internet via satellite radio with a subscription for data (Inmarsat or Iridium) or HF radio with a modem (Pactor) and subscription for internet connection (eg Sail Mail) is required.

Both satellite connection and HF-Radio with Pactor modem allow you to send and receive e-mail and download GRIB files. Both have too low bandwidth to surf the internet. There are satellite solutions that provide higher bandwidth with the possibility of a slow internet connection, but those solutions cost significantly more.


There are various restrictions on which communication equipment can be installed onboard. Some obvious are

  • Space and weight
    Can the boat handle a heavy antenna? Is there space to install receivers and transmitters close enough to the antenna to reduce signal losses in the antenna cable. Is there space on deck, mast, targa arch or in storage compartment
  • Energy consumption
    Is the electrical system able to supply electricity to the equipment that is installed?
  • Acquisition and operating costs
    What is the budget for long-distance sailing? What is the cost of spare parts? Do you need to prioritize something else?
  • Knowledge to take care of and maintain the equipment
    Do you have knowledge to be able to maintain and use the equipment? If not, what happens when it does not work or the only person on board who knows how it works is not there?

Our need

We wanted it to be easy to access the internet from several different devices (computers, mobiles, navigation systems). With a local WiFi network onboard with an internet connection, you can share the internet connection to several different devices. It would also be good to be able to connect devices with a network cable.

As a basis for choosing connection technology, we prioritized the type of information and how much data we need, and when we need it. This is what our needs looked like

AlwaysHigh30 MBWeather forecasts (GRIB files), report our location and receive and send important emails
AnchoredHigh15 GBSurf the internet to get information about the current situation in visited countries, find shipyards and spare parts, manage finances and update our social channels
AnchoredLow2 GBRead about what is happening in the world and at home
Cheap dataHigh2 GBDownload updates of charts and programs to computers (plotter, laptop, tablet and phones) as well as backup of important information to the cloud
Cheap dataLow80 GBStreaming of video and music
Need of information on the internet

Our solution

How shall we solve this?

We started from where we will be located. This is what determines what opportunities there are to connect to the internet. The rest is a matter of technology, money, and knowledge.

Most of the time onboard, we expect to be in places that have mobile coverage. In some places, there will also be WiFi to connect to. So therefore we basically have 3 different situations to deal with to connect to the internet.

ScenarioConnection technology
Within the coverage of WiFiDirect connection with laptop, tablet, phone. We opted out of WiFi routers due to uncertainty about whether they can handle web login
Within coverage of mobile networksMobile router with local WiFi network on board and some sockets for connecting a laptop with LAN cable. Direct connection by phone, good when you are out of coverage from your own WiFi network
No coverage of mobile networks or WiFiIridiumGo with local WiFi network on board
Connection technology in the different scenarios

Within mobile network coverage

Mobile router with a socket to connect equipment with LAN cable and an external antenna for better range. The router shares the internet connection via a local WiFi network that covers the entire boat.

As long as we are in the EU, we will use a Swedish data SIM and our Swedish SIM cards in the phones.
Outside the EU, we will get local SIM cards for use in the router. We may need to get an extra SIM card if we want internet when we leave the boat.

No coverage of mobile networks or WiFi

We have compromised and have an IridiumGo with an external antenna that we use for email, GRIB files (PredictWind) and to update our position automatically on a tracker page (PredictWind). To use IridiumGo, you download two Iridium apps to a smartphone or tablet. The phone connects to IridiumGo via its WiFi network.

We first bought a subscription from CTV-Service in Sweden and according to them, you could only buy a 12-month fixed subscription. This became too expensive because we could not pause the subscription as we had thought they would get. In the end, we finally managed to get them to cancel their subscription prematurely.

After that, we purchased a subscription via PredictWind that worked as we intended, ie we could cancel with 30 days’ notice. We also obtained several extra SIM cards to be able to start a new subscription when needed. Iridium has an option to pause a subscription, but then you still have a monthly cost that is higher than what it costs to get a new SIM card.

We opted out of HF-Radio due to installation costs. The HF radio also draws more power than the IridiumGo, although this was not a decisive factor for the choice.


Wifi Experience

Our experience from using WiFi networks, from eg the marina we have visited, is mixed. We have often had a bad connection because we had too weak a wifi signal. Often the WiFi networks are undersized (more people want to connect than it is built for, or you have too low bandwidth on the connection to the internet). This makes it difficult to connect or the connection is slow. Sometimes we have found a restaurant or bar with good WiFi, and then we have ordered an extra coffee or beer and stayed a little longer to email and update social media via the phone.

There may be WiFi at large anchorages and at buoys outside marinas, such as Sainte-Anne in Martinique and Ross Pt in Grenada. Since we did not have a WiFi router onboard, the signal strength was too low to connect. In addition, we heard that there were often problems with these networks. I do not know if it was due to technical problems with the network or if it was boats that were too far away.

Mobile router experience

The mobile router worked well in Europe with our Swedish SIM card. When we started using local SIM cards, the router could not connect to the 4G network, and instead we got a 3G connection or in some cases 2G. When we tried the SIM card in a smartphone, it was able to connect to the 4G network completely automatically. The first time it happened, we were able to download and install a new so-called. firm-ware in the router and then it could connect to 4G again. The next time it was time to plug in a new SIM card, it could only connect to 3G and there was no new firmware to install. It also did not help to manually enter connection information for mobile data traffic in the router. Since then, we have used our smartphones to connect to the internet and shared the connection with the phone’s WiFi hotspot.

Sharing via the phone’s WiFi hotspot has worked well as long as the phone has been located in the cockpit. When the phone is inside the boat, there is less coverage, especially when we are sailing or anchored in a bay far from any community.

Mobile data usage

The table below shows our approximate mobile data consumption for a month based on where we have been. I do not have any data for data consumption via WiFi, but I estimate it to be below 20 GB since we left Sweden. When we have had good WiFi, we have used to download updates to navigation systems, computers and telephones and update our electronic charts.

Type of informationEuropa/EUAtlanticOutside EU
e-post100 MB10 MB100 MB
Wheather1 GB12 MB1 GB
Googling1 GB02 GB
News/Social medias8 GB015 GB
Streaming80 GB00 GB
Data usage SIM-card

Mobile network experience

When we were outside the EU, we got a local SIM card for surfing. I usually ask at customs or at the marina which operator is best and where to buy a SIM card.

We think Digicell worked best and had the lowest price. Flow had poorer coverage and was a bit more expensive, at least when it came to data packages. Chippie had good coverage but had expensive subscriptions and, cumbersome handling of them. However, it was cheap to buy data traffic for an existing subscription.

When we arrived in Antigua we thought that our SIM card from Digicell would not work and since that country had just started to introduce restrictions for shops and how to move in the country (due to covid-19), we got Flow on the advice of the customs. Maybe our Digicell had worked.

The table below shows the countries in which the various operators we used in the Caribbean are located. The countries are arranged from north to south.

Saint MartinYesNoNoYes
St BartsNoNoNoYes
St EustatiusNoNoNoYes
St Kitts & NevisNoYesYesNo
St LuciaNoYesYesNo
St VincentNoYesYesNo
Trinidad and TobagoNoYesYesNo
Boldfaced blue Yes means that we was in that country and used that operator


The operator is called UTS but their mobile network is called Chippie. With their SIM card, you can make local calls to all countries in Chippieland (at least when I write this article). Chippieland basically includes the Dutch islands in the Caribbean.

  • I happened to have the surf end before I had filled up more and received three text messages about it, first that the surf was soon over and a few seconds later that it was over. A few more seconds later, an SMS came that the money I had to make international calls for was also over (200 SEK).
  • What had happened was that the surf started to cost per MB instead of being turned off as I thought. It was quick to consume the money that I put on the SIM card.
  • I think it was far too short time between the various SMSs.
  • To manage the subscription, you use the phone’s keypad and send * # codes and get voicemail menus to select options you want to do. A bit awkward and it feels outdated.
  • For example, if you ask how much data traffic is left to use and you have, for example, 5.52 GB left, the voice answers

You have fivebillionfivehundredtwentymillionthreehundredfiftyeightthousendninehundredtwentyeight bytes left


  • The operator that has mobile networks in most countries in Lesser Antilles.
  • By downloading an app to your phone, you can manage SIM cards and subscriptions in a simple way.
  • The SIM card we bought in St Lucia we could use in other countries as well.
  • If you have to make a lot of local calls, it may be worthwhile to get a new SIM card.
  • When a prepaid plan becomes too old, you can renew it and take the remaining data traffic with you to the next period.
  • You can use existing data in another country than you bought it.


  • Has mobile networks in slightly fewer countries than Digicell.
  • By downloading an app to your phone, you can manage SIM cards and subscriptions in a simple way.
  • We experienced that Flow had a little worse coverage at the anchorages on Antigua and almost no coverage at all at Barbuda at Cocoa Pt where we had anchored.
  • We only used Flow in Antigua and Barbuda, so I do not know if the SIM card would have worked in another country.

Satellite experience

  • We almost always have full signal strength since I connected the external antenna correctly.
  • During the crossing, we downloaded about 150 kB GRIB files twice every day and it took about 1.5 hours each time.
  • We noticed that the download stops after about 20-40 kByte, despite full single strength.
    I do not know what this is due to. Each time this happened, it took about 5 minutes for the system to detect that the transmission stopped, disconnect and disconnect the connection again.
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