hmmmm ...... just to be clear here. A "mifi" is a product name (an old one) that is technically a wireless access point.

These devices DO NOT connect directly to the internet they allow access to it via a specific network. The term "Wi-Fi" has traditionally been associated with a wired, local area network (WLAN). Like in your home you probably have copper wire or fiber running to a wireless router that then allows wireless access to the Internet. But there are also 4G/LTE networks. Each requires a different receiver in the device through which you want to connect to the Internet. Terms can be confusing. The terms Wi-Fi and Wireless Local Area network are often used interchangeably.

A wireless access point (Hot Spot), like the ones being talked about here for use on a boat in the BVI, receives a an RF signal in the 1.8 - 2.5 GHz, 2 - 8 GHz range. That's Digicel's 4G network throughout the BVI and ATT's 4G/LTE network in the USVI (actually East to about JVD).

Some portable devices (smart phones, tablets and lap tops) have 4G/LTE receivers built into them and as long as you are in range of a 4G/LTE signal you can access them .......

IF YOU HAVE A DATA PLAN and a Sim Card installed in your portable device with the provider you want to access it from. That can be a PITA within most of the BVI.

If you have a device that has a Wi-Fi adapter too, you can walk right up to Starbucks (or any public place that has a wireless access point) and for the price of a cup of coffee connect to the internet through their in house wireless LAN (usually bandwidth limited and you'll find that out if three are a lot of users signed on to it). Keep in mind, that is not the same as the phone companies 4G/LTE network.

Thus, the Digicel "mifi" (correctly referred to as a wireless access point or Hot Spot). If you get one of these from Digicel (a good solution to having Wi-Fi on board). You still have to purchase a data plan. You're accessing the internet through the 4G network not a wired LAN.

Digicel's data plans are reasonably priced. Figuring out how much data you need can be hard. If you stream video and/or watch movies you can go through 3 gigabytes in a hurry (that's a 30d, $50 prepaid amount). If all you do is surf and check email, you can get by with 500 Megabytes (around $10).

To make a long story short: If your primary cruising ground is going to be East of JVD and you need Internet access for multiple portable devices on board, go to a Digicel store in Tortola and get one of their hot spots (wireless access point)and a data plan that matches your user needs. Sales people in the store are very knowledgeable and friendly.