Winter’s on in the northern hemisphere, and travelers from all over are booking cruises to the Caribbean for a little sun. If a phone figures into that fabulous vacation, it’s important to know where mobile roaming speeds will slow down the fun. We examined Speedtest^® data from Q4 2019 for five popular Caribbean destinations to see which country has the best roaming speed, how roaming affects latency and how country of origin affects results.

Roaming speeds excel in the French Antilles

Roaming agreements are complex arrangements negotiated between individual mobile operators on a country-by-country basis. For travelers this means that mobile speeds can be very unpredictable abroad. Speedtest data showed Guadeloupe and Martinique had the fastest mean inbound roaming download speeds of all the countries on our list during Q4 2019.

On the other hand, visitors to Cuba and The Bahamas saw the slowest mean download speeds while roaming during Q4 2019.

Local speed does not predict roaming speed

We expect to see slow roaming speeds in countries with slow mobile speeds overall, because roaming relies on in-country networks. However, when we look only at the percent difference between roaming and local speeds, we see that local speed was not the only indicator of roaming speed.

For example, Antigua and Barbuda’s mean local download speed was the second fastest on our list during Q4 2019, but that figure represents a 75.5% decrease in mean roaming download speed. The result is that Antigua and Barbuda ranked third to last for mean roaming download speed during Q4 2019. Cuba showed the largest decrease in mean download speed between roaming and local at 82.9%. Martinique showed the smallest decrease at 4.2%.

Roaming’s effect on latency

Latency is a major pain point for consumers who are roaming outside of their home country. Roaming signals are routed from the country a consumer is visiting to their country of origin and then back to where they physically are with their phones.

Latency while roaming was highest by far in Cuba during Q4 2019. Roaming latency represented a 372.0% increase over local latency, which was also higher in Cuba than any other country on this list. The high roaming latency in both Guadeloupe and Martinique is likely both because local latency is higher there and because the majority of samples we saw in those locations were roamers from France, so the signals for roamers had to cross an ocean, twice.

Antigua and Barbuda and The Bahamas were tied for the lowest latency we saw for consumers roaming in the Caribbean during Q4 2019. These two countries also had the lowest local latencies during this period.

Performance varies widely by roamer’s origin and destination

Although Puerto Rico is a U.S. territory, visitors from the 50 states of the union had a faster mean download speed roaming in the Dominican Republic than they did in Puerto Rico during Q4 2019. Both were slower than the U.S. average download of 38.74 Mbps during that period.

Roaming download speed for U.S. visitors to The Bahamas were much slower than those seen in the other two locations and 19.4% slower than the mean download speed for residents of The Bahamas. Latency for U.S. roamers was also much higher in Puerto Rico than it was in either The Bahamas or the Dominican Republic. For comparison, mean latency in the U.S. was 47 ms during the same period.

Roaming upload speeds for U.S. visitors were much more similar between the three destinations than we saw on the download side. All were much slower than the mean upload speed in the U.S. of 11.19 Mbps during Q4 2019.

French visitors to Guadeloupe and Martinique experienced similar speeds and latency roaming in both locations, despite the sharp difference in local speeds. Considering the mean download speed in France was 44.19 Mbps and upload was 10.94 Mbps during the same period, these roaming speeds require a bit of an adjustment, but not painfully so. Latency, on the other hand, will require users to pack their patience, as mean latency in France during this same period was 41 ms.

Guadeloupe, Martinique, the Dominican Republic and Puerto Rico are among the best Caribbean destinations if roaming performance is a factor in choosing a cruise. Either way, multi-island travelers should be prepared for a variety of mobile roaming experiences in a variety of countries and aboard ships where roaming uses the ship’s cellular or Wi-Fi network.

If you’re a mobile operator interested in improving roaming performance to make your country even more attractive to foreign visitors, learn more about how Speedtest Intelligence^TM can help you.