How to Get Internet on a Boat
Your Cell Phone
Most boaters spend most of their time in places where their cell phones have service. If you're somewhere where your mobile phone gets a passable signal, you don't need to do anything fancy to get Internet. Obviously, you can browse the web and check email directly on the phone if you have a smartphone, but most likely, you can also turn it into a mobile hotspot so that you can share the Internet access with a laptop or desktop over wifi. If you're able to connect to an LTE network, your Internet connection may even be faster than you have at home. That said, the availability of cellular signals can be spotty. This approach is free and the easiest to set up, and can potentially provide the fastest connection. It is probably the best bet for two situations- people who mostly want Internet while docked and people who are just not all that pressed about being online all the time.One word of warning though- those "unlimited" data plans are not really unlimited. They have a "soft cap" where once you have downloaded a certain amount of data in a month, they slow your connection way, way, down. The amounts that they cap users at vary from carrier to carrier and change over time, but if you're using these services for full time Internet usage, you likely will hit the cap if you are streaming video and whatnot. You can actually get more data with some of the highest limited plans, like AT&T's 50 GB/month data plan, than you can get with the unlimited plan.
Boosting You Cellular Range
If you are going to be cruising around the coasts or rivers, drifting in and out of cellular coverage, and you are would find it frustrating to have to live without Internet for blocks of time, you still can probably take the cellular approach, you just need to slap on some gadgets that will boost your signal. The simplest option is a cradle that you just slide your phone into. I recommend the weBoost Drive 4G-S Cell Phone Signal Booster. It is powered off of a cigarette lighter-type port, so if you don't have one of those, you would need a converter. You also have to leave your phone in the cradle when you're using it, so it is probably most useful if you're using your phone as a mobile hotspot. Or, if you want to lock your phone into the cradle, you can use the weBoost Drive 4G-M which transmits the signal to your phone wirelessly.If you don't want to fuss around with your phone and you want a dedicated, always-on, cellular Internet connection with the strongest possible signal, your best bet is to install a proper cellular antenna and cellular modem. For the antenna, I would recommend the Wilson marine antenna (and whatever cables you need given your setup). Picking the right modem can be a bit trickier. You need to make sure of two things- that it works with your cellular carrier and that it accepts an external antenna. Here is a high end one that has one version that works with Verizon and another version that works with AT&T. Or, as with most cellular products, you can get cheaper equipment by signing up for a data plan. For example, with Verizon or AT&T.
WiFi
WiFi used to rank higher among the available options than it does today. For one, WiFi used to give you the fastest possible connections speeds, but today, LTE is typically going to be faster. For another, unsecured wireless networks used to be more common than they are today. That said, WiFi does still have its place. If you spend most of your time in a particular marina, and that marina has wifi, it is likely cheaper than cellular if you are going to be using up a lot of data. If you don't get an LTE signal in the marina, wifi will also probably be faster. And, if you get a strong signal in your slip, you might not need to buy or fuss with anything to use it. WiFi can also potentially be useful to cruisers because you will find some spots where you get an unsecured or inexpensive WiFi network where you don't get a cell signal. You can also boost your wifi signal to get better range, for example, with the Wave Rogue Pro or the Wirie. The Wirie also comes in a wifi/cellular combo, which is appealing, and you might consider it, but note that it does not support LTE, which is by far the fastest data option on cellular.SSB
As soon as you get too far out of range of all the cellular towers and wifi networks, your options drop off dramatically. The only affordable option offshore is Single-Sideband (SSB) radio. SSB is not actually an Internet connection at all. It is just a radio that some folks have set up a system to send and receive emails and weather information over. Sending and receiving email over SSB is cheap, but setting up and operating the radio does require some knowledge, and even a license. You can find a good tutorial on SSB email here. The problem, of course, is that it is extremely slow. If you are old enough to remember 14.4k modems, they were 7 times as fast as SSB is on its very best day in perfect conditions and realistically, most times, more like 15 or even 50 times as fast. The good news is, that is actually fast enough to send and receive text-only emails. Text is actually very small. It's the images and attachments that eat up the bandwidth.Satellite
If you need full-fledged Internet access offshore, you only have one option- satellite Internet. And, while there are much more affordable, faster, satellite Internet options on land, the options at sea are much slower and much, much, more expensive. Depending on how overloaded the satellite is, how crowded the area you are in is and how much you're willing to spend, the speeds can range from those of a very slow, very early, dialup modem up to the slowest options they used to offer for DSL connections. If you need complete coverage of the globe, you need an Inmarsat or Iridium based device and you will need to accept costs of up to $25 or $30 per Mb. for data. But, "Ku band" VSAT networks now cover most of the parts of the oceans that you're most likely to be in at a much lower cost and provide much faster service. The units are still quite pricey though. I'd suggest checking out the KVH V3 Tracphone.There are plenty of other specific products and services, probably other strategies entirely, and everybody has different experiences with them, so if you have some thoughts on the topic, definitely share them in the comments below!