Communications While Offshore Sailing


Last Updated on December 12, 2021 by Amy

A lot has changed since we took off to go cruising, and as we’ve learned, our communications plan has changed with the times.  Now it is easier than ever for us to keep in touch while we are offshore sailing, and we expect that the near future is going to see massive changes.

While there are certainly days where being incommunicado and hundreds of miles from our fellow humans sounds excellent, the truth is that we don’t want to be isolated and are actually looking forward with meeting and keeping in touch with both friends we meet on our travels as well as friends from home.  Communication gear on boats is a pretty complicated topic, but I’ve spent some time trying to wade through everything and we have come up with what we feel will be a pretty decent plan for keeping in touch.  

Satellite Phones

To start out, a satellite phone will be a major backbone of our communication systems.  It provides an easy way to do voice calls, and can also be used for data transmission, which in our case means emails.  Data speeds via sat phones are incredibly slow so we won’t exactly be reading CNN or laughing at the latest LOL Cat email, but if you use an email service that provides compression, text emails can be sent and received relatively quickly.  We plan to use emails to receive weather information, so this will be an important function for us.  I will cover some of the email services that I’m evaluating in another post.

The other important thing consider is the coverage map.  This isn’t quite like the early 2000’s cell phone plans where if you wandered out of your service area you paid large roaming charges.  With a sat phone, if you are out of the coverage zone, you won’t be able to make any calls/send any emails.  That can be a big problem if you’re in the middle of the ocean and need your phone.

Finally, the way satellite phones typically work is that you have “data minutes”. Your phone dials and connects using these “data minutes”, even when using the phone as a router to check emails and whatnot.

You purchase the phone and then you need a SIM card and plan (prepaid or monthly) from a service provider, just like you would your cell phone.

Service Plans

Here are an example of monthly service places through Roadpost, our original provider.

Iridium Go – $140/month – Unlimited Data/Text + 200 voice minutes

Iridium – $115/month – 200 minutes

Inmarsat – $110/month – 200 minutes

To give you an idea of how quickly your minutes will go, when out at sea, we check our email twice a day. This takes up to five minutes if your connection is strong, so let’s say:

five minutes x twice a day x twenty days at sea = 200 minutes

Now we use Predict Wind for our service provider:

150 minutes Unlimited data $139.95 /month

Iridium Go

We upgraded from an Iridium Satellite phone to an Iridium Go.  Almost every cruiser we meet has the Iridium Go.

With the Go, Iridium simplified the plans available. There’s only one package really: unlimited data and texting, plus 200 voice minutes a month. Our provider is Roadpost.

My biggest gripe about this system is that there’s no way to check my minutes.  For a very long time, we just weren’t using the minutes at all, but now we have weekly calls to our families.  Keeping these phone calls to less than a half an hour eats up at most 120 minutes a month.  However, the call quality is not great.  The call will be dropped about 3-4 times in the half an hour and there is a terrible lag.  There are many times that whatever local internet service we are using is not a fast enough or strong enough signal for a VoIP connection, and the Iridium Go is the better option.

External Antenna

We do have an external antenna for our Iridium Go.  We originally had the antenna installed in Spain when we were having trouble connecting our original Satellite phone with limited minutes.  The connection was still incredibly terrible, and our connection was getting dropped when we were checking our email and we were just devouring our minutes. 

When we switched to the Iridium Go we had unlimited data, so it became less expensive, but the dropped connection was still frustrating us. 

In New Zealand, David replaced the entire system – we upgraded to better cable, eliminated connectors and bought better quality connectors.  Now, we have no dropped connections while checking our email.

Iridium Antenna
Iridium Antenna

Offshore Email

We used to use offshore email hosted by Ocens.  We paid $200 a year for a custom email address.  While onboard Julia, we helped Susan and Tom set up their Ocens OneMail account, which allows them to check their regular gmail through the sat phone for $100 a year per email address.

We received weather forecasts through our offshore email by SailDocs which we used to download GRIB files and then we view the files on a program called ZY Grib.

Now, we use the simple and free myiridium.net email for our offshore email communications and we upgraded our weather data to Predict Wind. Since we will have a shorter sailing season for 2020-2021, we opted for the 3 month Predict Wind plan instead of a annual plan.

A few downsides for the myiridium email: we check it on our mobile phones, not our laptops, so we can’t download GRIB files. We can’t forward the myiridium email to our regular emails, so if someone emails us while we aren’t out at sea, it’s likely we won’t get that email for a while.


We only use the texting with other cruisers who also have the Iridium Go.  Those text messages are free. Depending on the provider, whoever I text on a cell phone may be charged for texting with a satellite number.

Data Speeds

The Iridium handheld data connection tops out around 2400 bps.  So remember those impossibly slow 14.4k modems?  Yeah, ours will be even slower.  If there was ever anything in life that may be able to teach me patience, this will likely be it.  Fortunately, the use of an email service that provides compression will increase things somewhat, but there will be absolutely no broadband internet using this method.


This is where Iridium really shines.  They have a system of 60 low-orbit satellites that offers coverage effectively worldwide.  Since we are on a circumnavigation, this was an important concern of ours.  

Iridium Coverage Map
Iridium Coverage Map


The latest offering from Inmarsat is the IsatPhone2 which again has been designed to be a rugged phone for the elements.  It offers impressive battery life as well as similar features to the Iridium Extreme.  In all honesty, the equipment was not the deciding factor in our decision as both seem to be high quality.

Inmarsat IsatPhone2
Inmarsat IsatPhone2

Data Speeds

Finding reliable reports of data speeds for these networks is a bit of a challenge, but I did find a few references to data speeds of around 1200-1500 kbps and several threads on Cruisers Forum referenced that the Inmarsat data speeds were slower than Iridium.  I’m aware that “fast” is a relative term in this instance, but going with the quicker network is what tipped this decision.


Inmarsat offers effective worldwide coverage, excluding the poles.  Since we aren’t really planning on communing with the polar bears or penguins, this wasn’t such a big deal.  However, the reported lag time due to the height of the satellite network was a concern.

Inmarsat Coverage
Inmarsat Coverage



The coverage offered by Globalstar ruled this one out immediately.  They have significant holes in their coverage once you get away from the coast which means I don’t think its very well suited for significant marine use.

Globalstar Coverage
Globalstar Coverage

Boat Tracking

We really like some of the blogs we follow (such as Two Fish) that have integrated maps showing where the boat has been.  And as we’ve discovered, there are lots of ways to do this.  I’m going to break it down into two categories, software and hardware.


A lot of the satellite service re-sellers (where you actually buy the airtime minutes for your sat phone) offer some sort of tracking application.  These are typically geared toward commercial users who are looking to track employees in the field or keep track of various assets as they move around the world.  That means they’re a bit expensive, have features we don’t really want or won’t use, and integration into this website would range from difficult to impossible.  The benefit of these type of services is that your Iridium Extreme Sat Phone (or ISatPhone2) can serve as the necessary hardware to send the information needed for tracking.  But integration into our website is a big factor for us, which lead to…

Spotwalla: Spotwalla is an awesome, free, personal location manager that offers support for multiple devices.   It will integrate into our website allowing us to share where we are in real time.  That will be prefect for those poor friends of ours who have to wait at a beachside resort while we sail to meet them.


The Spotwalla website offers a good list of devices that be used to integrate into their service.  These are the ones we evaluated:

Garmin InReach

We originally picked the (formerly Delorme) Garmin InReach for it’s tracking capability and we are VERY happy with it.  We paired it with SpotWalla to embed a map of our trip on our website and our position can be updated up to every 10 minutes.    We’ve also found that we can download the tracking information as a GPX file, and import it into a program like OpenCPN.  This also tracks our total mileage. 

You may be thinking – wait, doesn’t your Raymarine do that?  Well, yes, technically it does, except that three times we have gotten a single GPS position in a totally random location – like England – and those tens of thousands of false miles cannot be taken off our mile log.  So, we have our most accurate mileage reported by our InReach.  And how badass is it that we have a map with our entire path on it?

More and more though, the InReach is being thrown around as an alternative to an EPIRB.  That’s not our stance – we have an EPIRB and are keeping it.  The InReach SOS function has a large number of benefits compared to the EPIRB.  Here’s how the InReach SOS works:

  1.  A signal based on the Iridium satellite network is sent to the  International Emergency Response Coordination Center (IERCC) at GEOS.
  2. Within minutes, the device receives a confirmation from the rescue services.
  3. Here’s the most important part:  the InReach is a two-way communication device.  That means that rescue services will be able to send you a message regarding your rescue operations and you will be able to send messages back.  Image the increased effectiveness of your rescue when they know how many people are onboard, and the nature of the emergency.  If there is a medical emergency onboard, rescue services can be ready to treat during the rescue operation.
  4. GEOS is a private service.

For an example of a marine rescue:  https://www.garmin.com/en-US/blog/marine/inreach-u-s-coast-guard-rescues-two-sailors-dog-hurricane-irma/

The Baha-haha now requires boats in the rally to have two-way communication onboard. An EPIRB does not qualify. https://www.baja-haha.com/HowTo.html#Radios

SPOT Personal Tracker

This is a much simpler device (no screen) that offers very similar features to the inReach SE.  However, the disqualifying factor of the SPOT Tracker is that it runs of the Globalstar network and while the messenger has better coverage than the phones there are still significant gaps.  So while it may be cheaper, it was ruled out quickly.

SPOT Tracker
SPOT Tracker

Iridium Extreme Email

Spotwalla offers a method to update your location via email by sending them an email in a certain format detailing such items as your Latitude, Longitude, Date-Time and other options as well.  This would allow us to use our Iridium sat phone to send an email, but it would be a manual method of updating and wouldn’t be ideal.


Everything I read makes it sound like the world is getting smarter and locking up their wifi.  Bummer for us.  However, there are still opportunities to grab land based wifi signals for a cost, or that rare glorious unlocked wifi signal.  So because of that, we have a bitstorm Xtreme system that we installed on the boat in Florida.  It was recommended to us and was highly rated by Practical Sailor.  Open wifis were much easier to find in the Caribbean, where it worked a treat!

Bitstorm is no longer making their wifi extenders.

BadBoy Xtreme

Cell Phone

We both have unlocked Andriod phones. Every country we come to, one of the first things we do is to buy a SIM card. The data is usually cheap and much faster than our Iridium Go.  

Cellular Router

While in New Zealand we purchased an unlocked mobile wi-fi router (make sure it works in the region you are sailing).  We can take any SIM card and broadcast a signal throughout the boat.  We also purchased a cheap booster antenna to get a stronger signal.

This SIM card adapter has been handy to have so that we can use the same SIM card in either our router or our cell phones.  It converts from a nano (for the iPhones) to micro or standard SIM (for the router).  Also, we purchased a SIM card cutter, which we have used when nano SIMs aren’t readily available (like Tonga).  It fits into our cell phones a lot better than when the store employee takes a pair of scissors to the SIM card…

Another option is to get a device like a Tep Wireless to give you constant internet.

Additional Options to Consider


The single side band radio has long been used by cruisers to satisfy most of their communication needs.  When you combine an SSB with a Pactor modem, you can download email, just like we do with our Iridium Go.  There are also ways to make phone calls using SSB and a land based service, but this isn’t as plug and play as a sat phone, nor could it be taken with us if we travel or have to abandon ship.  The big advantage I see for SSB is the community they provide, as cruisers nets are very popular.  The significant downside to SSB is the upfront equipment cost which isn’t cheap.  Since I have zero prior experience with these systems, we would need a professional to install it for us as well.

Additionally, SSBs have a very steep learning curve. We played around with one onboard S/V Julia, and couldn’t figure it out, even with the instruction manual.

The Future of Internet Onboard

There are several options out there through both Iridium and Inmarsat to get “broadband” internet on the boat.  However, the equipment is extremely expensive and you can get speeds ranging from 150kbps to 432kbps (using Fleet Broadband).  For reference, I just ran a speedtest on our home internet connection and we have a 16Mbps connection.  So marine “broadband” is rather relative and we certainly wouldn’t be streaming the soccer matches over our internet connection.  

However, Starlink is rapidly approaching, and if we were to go out cruising full time again, this would be a game changer.


The connectivity/internet was not broken down in the budgeting blog post.  Here’s our info:

  • Iridium Go through PredictWind: $137/month = $1,644/year
  • Domain Registration through Namecheap: $65/year
  • Website hosting through Dreamhost: $120/year
  • InReach: $28/month = $336/year
  • Email through Google: $100/year
  • Misc internet (SIM cards and wifi): $500-1000/year

Total yearly: $3,000 – 3,500

So that’s all the gear we have to keep us in touch with the world!  We think we’re doing pretty good – we are posting to the blog twice a week (with pictures) and posting videos to YouTube every 10 days or so, and in the grand scheme of things, communications are a small part of our overall budget.

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  1. Hi Amy,
    Thanks for the great article. What do you see as the redundancy system for the Iridium Go? Do you have one? We bought a Go and are tossing up buying a sat phone in addition in case the Go calling feature doesn’t work or if we have to board the Liferaft. Appreciate any thoughts!

    1. Hey Grace! We still have an Epirb and a InReach Tracker device. The inReach allows two way communication with rescue services and family, so that’s a great one to have.

  2. https://maritime.viasat.com/ is now offering a high speed Internet solution. Their price point is way out of most cruisers budget but for those who make their living as a digital nomad at least they provide an alternative to land based Internet connection for work.

  3. Hello Y’all,

    Looking at the annual expenses and this page for clarification, I am not seeing a reason explained for the continuous increase in communications costs. It increased every year and I would be interested in knowing if this is because of an increase in internet usage or does iridium jacking it up that much each year? Or, do you keep adding functions or equipment?

    1. The increase is almost completely for local data. For our first year, internet was either freely available (in the Caribbean) or simply not available (French Polynesia). Additionally our videos have gotten longer and high quality, so we pay more to upload our videos than we did in the beginning.

  4. Hey David & Amy,
    Great info as always. Watched the youtube of the projects with the updated antenna cable.

    What length would you recommend to get from the spar to the nav station?
    Jeff & Debby

  5. Thanks for the info! I am considering the Iridium Go for our RV as we plan our adventures into areas of Canada remote from any mobile signal. I would be interested to know more about the antenna you decided to use. Any tips on antenna, cables, and connectors?

    1. We don’t have specific info on the antenna or cables. Here’s a few tips though: use the biggest cable you think you can with the best quality. It’ll be worth it. You want the fewest connectors though, so make sure the cable can bend appropriately, as sometimes it’s better to bend the cable than add an additional connector. Our antenna had a stand, but it wasn’t high enough to get a curve in the cable instead of a connector, so we had a custom one built.

  6. I love watching you guys!!! We are going to retire in two years and sail exactly like you have been doing!!! The info you share is PRICELESS for those of us planning our own adventure!!!! I’m hoping when we get started, we would be where you are and be able to “meet in the middle of the ocean” as well!!!! Thank you!!!!!!

  7. Thanks again for the detailed information. I’m keeping notes so that when we take the plunge in a few years we don’t have to reinvent the wheel.

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