Many of us cruise with quite a few battery-powered devices that we want to keep charged, but cruise ship cabins don’t have as many outlets as we’d like. Common power strips are prohibited from cruise ships for safety reasons, and there aren't "cruise ship power strips", but there are alternatives. Let’s look into your options, and briefly cover why power strips aren’t allowed.
Why can’t I use a power strip from home?
In short, fire is the greatest danger at sea, and these devices may not prevent faults like they’re supposed to. I’ll try and keep this simple so we don’t go off an electronics-engineering deep end (only to be corrected by actual electronic engineers). Your home power strips will certainly work on a cruise ship, but they aren’t safe for a rather ironic reason. The circuit breaker that is supposed to protect you from fire due to short-circuits or overload may not work right on a ship. These breakers generally rely on disconnecting the ‘hot’ wire in your AC circuit, leaving only the neutral and ground wires connected. Because a ship generates electricity in a different way, and has a somewhat different method of grounding, there is a chance that the circuit could become overloaded, but tripping the power strip’s built in breaker will not stop the flow of electricity. If you want to better understand this, I’d check out this article from the US Coast Guard.
What are the alternatives?
USB Power Ports can be a handy accessory at home, but in a cabin with limited electrical outlets they can be very handy, mostly if the majority of your devices charge via USB. I personally use this model from Anker (who makes great stuff). It not only has five standard USB ports (USB A) but it also has a USB C port which supports USB power delivery, meaning you can charge phones that use USB C, but also laptops such as certain model Macs, the Dell XPS series laptops, and others. If you’re not familiar with USB C, trust me, you will be in the next year or two, so this may be a good choice. If you want to stick with a slightly cheaper option without USB C, this model has only USB A ports.
European Outlet Adapters are another accessory to help you out is something you may already own. A simple $5 adapter that gives you an extra outlet (or two). Most cruise ships supply both 110VAC and 220VAC power to cabins and public areas. In North America we use 110VAC, and these are the outlets you likely use in your cabin. On almost every cabin I’ve ever had however, there is at least one 220VAC outlet (Type F, as used in most of Europe) near the vanity. As more and more of the electronics we use are dual voltage, a cheap adapter is enough to use this outlet with most of your devices. It’s important to know that while it’s not common, you must verify that the charger or other device you’re plugging in accepts ~220VAC or you risk breaking whatever you plug in. I personally have a number of these adapters for travel, but find this one to be really well made, and it even gives you a second outlet!