Want to get a handle on cellular service in your area, or someplace you are headed? Go to the CellReception.com website and enter a city and state.

You'll get an interactive map, and you can scroll and zoom to find the where the cellular signal towers are located. Click on "Comments" and you can see what other people have said about different towers. It may surprise you to see how many towers are in your own home area.

Next, go to WirelessAdvisor.com and enter a zip code. That will show you all of the frequencies supported by the towers in that area.

Together, these tools can show you what you are working with when it comes to getting solid reception on your boat.

Here's a map showing towers in the San Francisco Bay area.