# GigSky Cruise eSIM Review: What It Does and What It Costs > GigSky sells one of the few eSIMs that works at sea, on the ship's maritime network. Here is what it does, who needs it, and the cheaper port only option. Source: https://viasimo.com/magazine/gigsky-cruise-esim-review/ Published: 2026-09-21 Tags: cruise, comparison, travel-esim, buying-guide --- GigSky sells cruise specific eSIM plans that work on the maritime cellular networks installed aboard ships, which puts it in a small category: most travel eSIMs are land network products and stop working once the coast is out of range. That capability is real, and it is priced accordingly, because maritime capacity is delivered by satellite rather than by cell towers. This review explains what the product actually does, who it makes sense for, how to set it up, and the much cheaper arrangement that covers what most cruise passengers actually need. In this guide: - [What GigSky sells for cruises](#what-gigsky-sells-for-cruises) - [Why maritime data costs what it does](#why-maritime-data-costs-what-it-does) - [Who should buy it](#who-should-buy-it) - [Who should not](#who-should-not) - [How to set it up on a ship](#how-to-set-it-up-on-a-ship) - [Airalo, Holafly and other travel eSIMs on a cruise](#airalo-holafly-and-other-travel-esims-on-a-cruise) - [What to verify before you buy](#what-to-verify-before-you-buy) - [The cheaper arrangement](#the-cheaper-arrangement) - [The port day half, from Viasimo](#the-port-day-half-from-viasimo) ## What GigSky sells for cruises Two different things sit under the same brand, and confusing them is the main way people misjudge the product. - **Land plans**, which work in port on local networks exactly as any travel eSIM does. - **Cruise or maritime plans**, which are permitted to use the onboard cellular systems fitted to supported ships. The second is the differentiator. A ship's onboard system is a small cellular network aboard the vessel whose traffic is backhauled by satellite. It is a real mobile network, which is why your phone finds it, and it is normally reachable only through international maritime roaming billed by your home carrier at very high rates. A maritime eSIM plan replaces that billing relationship with a prepaid one. Coverage is vessel by vessel rather than cruise line wide, so support for a given sailing depends on the specific ship. Check your vessel and confirm current pricing on the provider's own site before buying, because maritime rates and ship lists both change. ## Why maritime data costs what it does The cost is structural, not a markup decision. Data reaching a ship in open water travels by satellite, which is scarce, expensive capacity shared across everyone aboard. A land cell tower carries orders of magnitude more traffic for a fraction of the cost. That is why every maritime option is expensive relative to land plans: ship wifi packages, maritime roaming from your home carrier, and maritime eSIM plans alike. The differences between them are in how you are billed and how predictable the bill is, not in the underlying economics. Among the three, prepaid maritime plans and ship wifi packages have the advantage that the price is known in advance. Home carrier maritime roaming is the one that produces the bills people talk about afterwards, and our [cruise internet guide](/magazine/cruise-internet-guide-esim/) covers how those charges accumulate. ## Who should buy it A maritime plan earns its price in a few specific situations. - **You need to be reachable on sea days for work**, and a wifi only solution with a login does not fit how you work. - **You want data on deck and around the ship** without connecting to wifi each time. - **The ship's wifi package is poor value** on your sailing, which varies widely by cruise line. - **You are on a long crossing** with several consecutive sea days and cannot be offline for all of them. If one of these describes you, price it directly against the ship's own package for the same voyage. They are the only two products that solve the sea day problem, so that is the real comparison. ## Who should not Most holiday cruisers, for one reason: sea days are the part of the holiday you are paying to spend at sea. Port days are where phones actually get used, for maps, ride hailing, restaurant bookings and photos, and port days run on ordinary land networks at ordinary prices. Buying maritime capability to cover days you will spend ashore is the same mistake as buying a full voyage wifi package for a port heavy itinerary. The [best eSIM for a cruise ship](/magazine/best-esim-for-cruise-ship/) guide works through sizing a plan from a port list, and the figures are small: 500 MB to 1 GB per port day, so 3 GB to 5 GB for a week long sailing with four calls. ## How to set it up on a ship The installation is standard, and the two settings that matter are the same on any eSIM. 1. **Buy and install before you sail**, over home Wi Fi. Installing needs an internet connection, and the ship is the worst place to discover that. 2. **Confirm your vessel is supported** by the plan you bought, not just your cruise line. 3. **Keep the line switched off at sea until you intend to use it.** Maritime networks are the one place where an accidental connection is genuinely expensive. 4. **Enable the line and switch on [data roaming](/glossary/data-roaming/) for it** when you want to connect, and set it as the data line. 5. **Turn your home line's data roaming off** for the whole voyage, so it can never register on the ship's network alongside the eSIM. Step five is the one that protects you regardless of which product you buy. Our [avoiding roaming bill shock](/magazine/avoid-roaming-bill-shock/) guide covers the exact settings, and [what airplane mode does](/magazine/what-does-airplane-mode-do-esim-roaming/) explains why it is the safest state at sea. ## Airalo, Holafly and other travel eSIMs on a cruise Airalo, Holafly and other mainstream travel eSIM providers sell land network plans. On a cruise they behave the same way: full service in port, nothing in open water. That is normal and expected, not a defect, because their plans ride local operators' networks and those are out of range at sea. So the practical difference between providers, for a cruise, comes down to the land side: which countries the plan covers against your port list, how much data you get for the money, and how the validity window is counted over the full sailing. Our comparisons of [Airalo alternatives](/magazine/airalo-alternative/) and [Holafly alternatives](/magazine/holafly-alternative/) cover those differences, and [the cheapest eSIM plan](/magazine/cheapest-esim-plan/) guide covers the price per gigabyte method. The one thing no land based provider can do is sell you working data at sea. Any claim otherwise deserves a careful read of what network the plan actually uses. ## What to verify before you buy Maritime plans change more often than land ones, and the details that decide whether the plan works for you are all checkable in a few minutes on the provider's own site. Confirm your specific ship, by name, appears in the supported vessel list, since coverage is fitted vessel by vessel and two ships in the same fleet can differ. Confirm the current price and what unit it is sold in, because maritime plans are sometimes priced per megabyte rather than per gigabyte and the two look very different at a glance. Confirm whether the plan also covers your ports, or whether it is sea only and you still need a land plan. And confirm what happens when the allowance runs out, since a maritime plan that silently continues at pay as you go rates is the same exposure you bought it to avoid. Any provider selling a maritime product should answer all four plainly. If a detail is hard to find, treat that as information. ## The cheaper arrangement For the large majority of cruise passengers, the cheapest setup that works is: 1. A small travel eSIM covering the countries on your port list, sized at 500 MB to 1 GB per port day. 2. Mobile data and data roaming switched off on every line at sea. 3. The ship's lowest wifi tier, bought only if you actually need to be reachable on sea days. That gives you ordinary data prices for the days you are ashore and using your phone, no exposure on the days you are not, and a known ceiling on the sea day spend. Plans for the countries on your itinerary are on the [destinations index](/destinations/), and sizing for a specific sailing is covered in the [cruise ship eSIM guide](/magazine/best-esim-for-cruise-ship/). ## The port day half, from Viasimo Whichever way you solve sea days, you still want cheap data ashore, and that is an ordinary land plan bought for the countries on your port list. [Viasimo](/) sells prepaid travel eSIMs for more than 190 destinations with the covered countries and the full price shown before you pay, which is the check a cruise itinerary actually needs. Plans are one off with nothing renewing, the QR code arrives by email within minutes, and installation happens in your phone's settings with no app to download. Because it is data only, your home number stays reachable on your existing line, which matters on a ship where you want that line's data roaming firmly off. Start with [Europe](/destinations/europe/) for Mediterranean sailings, or [the USA](/destinations/usa/), [Mexico](/destinations/mexico/), [Italy](/destinations/italy/) and [Greece](/destinations/greece/) individually, from the [destinations index](/destinations/). If you would rather start from the plans themselves, the [eSIM plan picker](/esim/) asks for your destination and your trip length and shows you what fits. ## Frequently asked questions ### What is the GigSky cruise eSIM? GigSky sells cruise specific eSIM plans designed to work on the maritime cellular networks installed aboard cruise ships, which is something standard travel eSIMs do not do. Ordinary travel plans rely on land networks and stop working a few miles offshore, whereas a maritime plan connects to the ship's own onboard system. The trade off is price: maritime capacity is delivered by satellite, so it costs far more per gigabyte than any land plan. It is a specialist product for people who need connectivity on sea days, not a general travel eSIM. ### Is the GigSky cruise plan worth it? A maritime cruise plan is worth it if you genuinely need to be reachable on sea days and the ship's own wifi package does not suit you, for example because you need a phone line rather than wifi calling, or you want data on deck without a wifi login. For most holidaymakers it is not, because sea days are the days you chose to be at sea and the ship's wifi covers the occasional need. Compare it against the ship package and against simply being offline before buying. ### How do I use GigSky on a cruise? The setup is the same as any eSIM: buy the plan, install the profile over wifi before you sail, then enable the line and switch on data roaming when you want to use it. The difference is which network it is permitted to use, which includes the ship's onboard system on supported vessels. Check that your specific ship and cruise line are supported before relying on it, because maritime coverage is vessel by vessel rather than line wide, and confirm current pricing on the provider's own site since maritime rates change. ### Do Airalo or Holafly work on a cruise ship? Airalo and Holafly sell land based travel eSIMs, so their plans work in port on the local network and not in open water. That is the normal behaviour for a travel eSIM rather than a shortcoming, since land networks are simply out of range at sea. If you buy any standard travel eSIM for a cruise, treat it as a port day plan. For data on sea days the options are the ship's wifi package or a specialist maritime plan. ### What is the cheapest way to stay connected on a cruise? The cheapest arrangement for most passengers is a small travel eSIM for port days combined with keeping mobile data off at sea, adding the ship's lowest wifi tier only if you need to be reachable. Port days use 500 MB to 1 GB each, so a week long sailing with four calls needs only 3 GB to 5 GB, which is inexpensive. The expensive mistakes are buying a full voyage wifi package to cover days you will spend ashore, and leaving data roaming on at sea. ### What is the cheapest way to cover port days on a cruise? Port days run on ordinary land networks, so an ordinary travel eSIM covers them at ordinary prices. Viasimo sells prepaid plans for more than 190 destinations with the covered country list shown before you pay, which lets you match a plan to your port list by name rather than by cruise region. Sizes small enough for port day use are inexpensive, and the QR code arrives by email within minutes so you can install before you sail. ### What are the GigSky cruise plans? GigSky sells two different things: ordinary land plans that work in port like any travel eSIM, and cruise or maritime plans permitted to use the onboard cellular systems fitted to supported ships. The maritime plans are the differentiator and are priced well above land plans, because capacity at sea is delivered by satellite. Coverage is vessel by vessel, so check your specific ship. ### How do you use GigSky on a cruise? Setup is the same as any eSIM: buy the plan, install the profile over wifi before you sail, then enable the line and switch on data roaming when you want to use it. The difference is which networks the plan may use. Confirm your specific vessel is supported before relying on it, and keep the line off until you intend to connect. ### Does GigSky work on MSC and other cruise lines? Maritime coverage is fitted vessel by vessel rather than cruise line wide, so support depends on the specific ship rather than on the operator's name. Two ships in the same fleet can differ. Check your vessel by name in the provider's supported ship list before buying, and confirm whether the plan also covers your ports or is sea only. ### Does an Airalo cruise eSIM work at sea? Airalo and Holafly sell land based travel eSIMs, so their plans work in port on local networks and not in open water. That is normal behaviour for a travel eSIM rather than a shortcoming. If you buy any standard travel eSIM for a cruise, treat it as a port day plan, and cover sea days with the ship's wifi package or a specialist maritime plan. ### Is the GigSky cruise eSIM worth the money? A maritime plan is worth it if you genuinely need to be reachable on sea days and the ship's wifi package does not suit you. For most holiday cruisers it is not, because sea days are the days you chose to be at sea and port days run on ordinary land networks at ordinary prices. Price it directly against the ship's own package. ### Does a Holafly cruise eSIM work at sea? Holafly sells land based travel eSIMs, so its plans work in port on local networks and not in open water. That is normal for a travel eSIM rather than a shortcoming, because land networks are out of range at sea. For sea day data the options are the ship's own wifi package or a specialist maritime plan.