Tides and currents shown on a smartphone.

GPRS (General Packet Radio Service) is an enhancement to GSM networks. GPRS can give you data rates between 30 Kbps and 90 Kbps. EDGE (Enhanced Data Rates for GSM Evolution) also offers data rates between 30 Kbps and 90 Kbps but is generally slightly faster than GPRS.

3G (3rd generation) refers to high transfer speeds giving you the pipeline to handle streaming video, music and other data-intensive features. There are several different types of 3G networks, including EV-DO and HSDPA. EV-DO (Evolution-Data Optimized) is a CDMA enhancement that increases the data speed to between 144 Kbps and 2 Mbps allowing you to handle streaming video and music. HSDPA (High-Speed Downlink Packet Access) is an upgrade to GSM networks offering higher data rates.

AT&T and Cingular merged last year and are now simply called AT&T. They support a large GSM network with GPRS over 100 percent of their coverage area. They have EDGE high-speed data on most of their network. In addition they have 3G data support with HSDPA available in most major metropolitan areas.

Verizon uses a CDMA network with high-speed EV-DO data technology in most areas. Their coverage area encompasses the United States, including Hawaii and Alaska, and Puerto Rico.

Sprint's network utilizes CDMA network technology. In addition they offer EV-DO high-speed data technology in most areas. They are also building a separate WiMax network offering faster speed than EVDO. Sprint's coverage area is the continental U.S., Hawaii and Puerto Rico.

T-Mobile had the first nationwide GSM network and GPRS service. They have EDGE high-speed data on most of their network. Coverage is nationwide in the U.S.

There are many other mobile network providers. You will need to determine which providers are available in your area and in the areas where you intend to take your boat. Armed with an understanding of the terms outlined above, contact each provider to determine which offer the services you need.

CHOOSING A PLAN

The next important step is selecting your plan. The number and types of plans being offered seems to increase exponentially each month. While we tend to think of choice as a good thing, it can also lead to confusion and poor decisions.

There are several things to keep in mind when considering a plan for use on your boat. First, all minutes are not created equal. There are "voice minutes" and "data minutes" (or bytes transferred). When you are making a phone call to check on the availability of a slip for the night, you are using your voice minutes. When you go on the Internet to check which marinas are nearby, you are using data minutes. So when considering a plan, make sure you look at the data minutes portion of the plan.

Each mobile network provider offers a variety of data plans for connecting your smartphone to the Internet. We strongly suggest selecting an "Unlimited Data Plan." Most of the carriers are now providing unlimited voice and data plans bundled together for about $100 per month. If you use a lot more than the minimum number of voice minutes per month, these new plans can save a lot of money and give you an unlimited data plan at the same time. By themselves, unlimited data plans typically cost between $20 and $50 per month.

Unlimited data plans offer a single monthly charge for unlimited data access. This allows you to budget precisely what your costs will be – and stop worrying about overages. Plans that are lower to start with often charge for additional bytes transferred, and that can quickly add up. If you plan on using your mobile phone for some of the boating specific applications we will be covering, you will definitely want an unlimited plan. When you have real email and web access on your phone, the uses will grow and the unlimited data plan will become the obvious choice. You'll find that you have access almost all the time for your laptop, too (although you won't be powering it up as much if you have a smartphone).

Find out if the plan allows you to turn off your data plan when you are not using it and if there are any restrictions. Many providers allow you to turn the data portion off and on per day, and will prorate the charges accordingly. This can be a real savings if you go cruising for part of the year or only want data access for longer trips and not for daily outings.

Also, be sure to ask what your overall monthly bill will be, including all taxes and fees that apply. Armed with a basic understanding of the most common terms used to describe mobile networks, the difference between feature phones and smartphones, and some sense of how you will be using your phone, you should have a greater comfort level when you approach a mobile network provider with questions, and be better able to understand their answers. In the weeks ahead we'll look at phones, applications you may find useful and some add-on equipment that can enhance connectivity.

And if all this gives you a headache, fear not. When you find that perfect out-of-the-way anchorage and want to just sit and enjoy, there's an off button on that phone.

NEXT WEEK: Installing Equipment to Increase Your Onboard Access to Mobile Networks