Onboard Communications for Cruisers: Staying Connected in the Caribbean

In a Nutshell...

When you’re out cruising, your comms setup is as much a part of your safety gear as your life raft. The best strategy is a layered approach. It should start with a solid VHF radio, which is your lifeline for local safety and chatter. You then back that up with a local SIM or eSIM for day-to-day use in port. For staying in touch at sea, a modern satellite system like Starlink has become a genuine game changer, providing both high-speed data and a crucial backup for emergencies. Layering these technologies ensures you’re never truly out of touch, no matter where you drop the hook.

Prickly Bay, a popular anchorage in Grenada, West Indies.

During Covid, we were locked down aboard our boats here in Prickly Bay, Grenada. It was VHF radio that kept us all sane.

What’s the Story with VHF Radio for Cruisers?

Is Getting a Local SIM Card Worth the Hassle?

How Starlink Has Shaken up the Market

How Do You Put Together the Right Comms Strategy?

Summing Up

Frequently Asked Questions

For many of us, staying in touch with the world is a real priority. Thankfully, the good news is that local mobile networks down in the Caribbean are generally pretty reliable and affordable. Picking up a local SIM card is dead easy in most of the main islands, like St Martin or Grenada. It’ll get you decent data coverage for a fraction of the cost of roaming. That said, I've found the quality can be hit and miss, especially when you’re hopping between islands. For offshore passages and real emergencies, a satellite phone is still a much better bet. Sure, it’s a big investment, but it’s one that gives you peace of mind when you’re far from shore.

For everyday communication, though, the trusty VHF radio is your most important tool, not just for ship-to-shore calls, but also for the daily "cruiser nets" where you can get updates on weather, local events, and a heads-up on everything from fresh produce to spare parts.

What’s the Story with VHF Radio for Cruisers?

Even with all the clever gadgets we have these days, the VHF radio is, without a doubt, the most important bit of comms kit on any cruising boat. It’s the maritime equivalent of a universal party line, and its most critical function is safety. The VHF operates on a line-of-sight basis, so its range is limited. But, as I've found over the years, that’s actually a real benefit in an emergency. When you transmit a Mayday call, every vessel within range hears you, and it’s often the nearest boats that can offer help.

Modern VHF radios come with Digital Selective Calling, or DSC, as we all call it. When connected to a GPS, pushing the red ‘DISTRESS’ button sends an automated digital alert with your boat's unique identification number and exact position. It’s a vital safety feature and one every sailor should be properly trained on. For the ultimate peace of mind, many sailors also carry personal or vessel-mounted emergency beacons. These beacons, like an EPIRB or a PLB, are your last line of defence in a life-threatening emergency. The VHF is also the hub for local 'cruiser nets,' a beloved tradition in the Caribbean. These are scheduled daily broadcasts where you can catch up on local knowledge, get the weather forecast, and hear about everything from fresh fish to spare parts.

Is Getting a Local SIM Card Worth the Hassle?

When you’re down in the Caribbean, sticking with your home mobile provider is a seriously expensive mistake. The international roaming charges can quickly rack up to a shocking bill. The most practical and affordable option is to get a local SIM card (or a regional eSIM) from providers like Flow or Digicel. You’ll find mobile phone shops in most of the main towns. A local SIM will get you affordable data plans that are perfect for checking emails, using navigation apps or streaming a movie while you’re at anchor in a bay.

However, cellular signal isn’t consistent across the region. While it may be strong in a port or popular anchorage, it can vanish completely on an offshore passage or in a remote bay. To help with this, many cruisers use a cellular signal booster. These devices use an external antenna to grab a weak signal and amplify it, often turning a frustratingly slow connection into a reliable one. It’s a bit of a faff to set up, but it can make a big difference.

How Starlink Has Shaken up the Market

For years, the choice for satellite communication was pretty limited to systems like Iridium or Inmarsat. These were brilliant for offshore voice calls, emergency comms and slow, text-based emails and weather faxes. But they were incredibly expensive and just didn’t have the bandwidth for modern internet use.

Starlink has changed all of that. The service, which uses a constellation of low-Earth orbit satellites, gives you high-speed, low-latency internet access that was once confined to land. For a cruiser, that means you can work remotely, stream content and make video calls while at sea, as long as you’ve got a clear view of the sky. The most sensible plan for us cruisers is the "Starlink Mobile-Regional" plan, which you can pause and unpause on a monthly basis, offering a ton of flexibility.

While Starlink is a complete game changer, it’s not without its drawbacks. The system gobbles up a lot of power, which can be a real headache for boats with limited battery capacity. It’s also not a replacement for your trusty VHF radio for safety. Furthermore, while the service is operational across the region, some island nations haven’t officially approved it for use, and the regulations can vary from country to country, so it’s always worth checking the local laws.

How Do You Put Together the Right Comms Strategy?

When you’re trying to work out your comms strategy, it's best to think in layers. Your personal approach will depend on your sailing style, but here’s a clear guide to the various systems.

System	Primary Use	Pros	Cons
VHF Radio	Safety, ship-to-shore, local nets	Essential for safety, widely adopted, no subscription cost	Limited range, no data or text
Local SIM/eSIM	In-port internet, phone calls	Affordable, fast data in coastal areas, flexible	Coverage inconsistent offshore, requires local purchase
Starlink	High-speed internet at sea, email, streaming	High speed, relatively affordable, low latency	High power consumption, regulatory issues, not a safety radio
SSB Radio	Long-distance voice nets, slow data	Very long range, good for community	High cost, complex installation, slow data
Traditional Sat Phones (Iridium)	Global offshore voice calls, emergencies	Truly global coverage, reliable voice calls	Very high costs, very slow data speeds

Summing Up

While the digital landscape for cruisers has changed dramatically, the core principles of communication at sea remain the same. The best approach is to build a layered system that ensures you have a reliable means of communication for every scenario, from a local Channel 16 call to a long-distance connection. By combining the simplicity of a VHF radio, the affordability of local data and the power of satellite internet, you can enjoy the peace of mind that comes with knowing you are always in touch. Together, these tools form a robust communication suite that, when paired with other key navigational electronics like AIS, ensures you are always prepared. You can find more comprehensive information on this topic and other essential cruising guides in our article: Sailing in the Caribbean: Information for Skippers & Crew.

Frequently Asked Questions

1. Is a VHF radio a legal requirement?

While it's not a legal requirement in every country, carrying a VHF radio is a fundamental safety measure and is considered standard practice for all seagoing vessels. It’s just not worth being without one.

2. Is a local SIM card better than using my home plan?

For cruisers, a local SIM is almost always a better choice. It’s significantly cheaper than international roaming and gets you reliable data access in the islands. Trust me, you don’t want to see that bill when you get back home!

3. Will my home-based Starlink plan work in the Caribbean?

You should check the specific terms of your plan, as they're always changing. The "Starlink Mobile-Regional" plan is designed for use in different countries within a continent, which makes it ideal for cruising the Caribbean.

4. What is DSC and why is it important?

DSC stands for Digital Selective Calling. When connected to a GPS, it allows you to send an automated digital distress signal that includes your precise location, dramatically increasing the speed of a rescue response. It’s a real lifesaver.

5. How much data do cruisers typically use?

This varies widely, but with the arrival of high-speed satellite internet, many cruisers now use a similar amount of data as they would on land, from a few gigabytes to hundreds, for work, social media and entertainment.

6. Do I need a licence to operate an SSB radio?

Yes, you do need a special licence to operate an SSB radio. In the UK, this would be a GMDSS Restricted Operator’s Certificate (ROC) or a General Operator’s Certificate (GOC), along with a ship’s radio licence for your vessel.