A chartplotter is an electronic navigation system that combines a GPS receiver with the capability to display electronic maritime charts, enabling the boat operator to continuously monitor the position and movement of his or her craft in relation to the surrounding physical environment, both above and below the water. Many boaters often refer to a chartplotter simply as a GPS unit but I like to keep things a bit salty and refer to them by their more proper name.

With an integral processor combining GPS data with electronic charts, a chartplotter pinpoints the location of the host vessel and can use the GPS data to calculate boat speed and direction, as well as determine the time and distance to the destination or next waypoint. It displays all this data in real time so that a navigator knows exactly where his or her boat is and where it is heading, as well as continuously updating its position relative to its surrounding physical environment. Units will have either a built-in internal antenna or an external antenna that requires relatively painless mounting. Both function well but if you are considering flush-mounting your unit, contact your prospective retailer or manufacturer for possible loss of signal strength if using a built-in antenna. This is really not an issue with the majority of available plotters, but is food for thought.

Mariners often use chartplotters to pre-load routes that can then be edited or manipulated at any time before or during time underway. Some plotters allow the navigator to store hundreds of routes at a time for future use. Previously navigated routes can easily be stored and retrieved. Each route consists of a number of waypoints to assist navigation and avoid hazards, such as sand bars, shallow rocks or reefs, and known navigational hazards. These are represented by longitude and latitude references and are depicted on a screen to give the user a visual representation of the watercraft's surroundings. Each waypoint is a numbered position and as a vessel progresses past each one the system indicates the distance travelled and course remaining until the next waypoint. Another function of these machines is the ability to show if the boat has strayed off course and will provide information to correct the bearing in order to arrive at the next waypoint. Fisherman can easily store, manage, and locate very specific locations for more enjoyable and productive trips. I, being a devout structure fisherman and safety conscience boater, consider a quality and user-friendly chartplotter, as a near necessity. I'm partial to the Northstar and Lowrance brands but that may be from years of use and a distinct familiarity with their features and controls. Do a little research and the right machine for your usage requirements will become apparent as today's market is loaded with good machines from various manufacturers. In another article I will discuss the sometimes daunting task of how to name, manage, and organize all the hangs, piles, and wrecks that often clutter a fisherman's plotter.

With the combination of GPS functionality and embedded charts, chartplotters have become an essential navigational and fishing tool which is relatively inexpensive to buy and easy to install and use on any type of watercraft. With a single chip now capable of storing electronic charts for an entire seaboard, they are remarkably cost-effective marine safety, navigation, and fishing tool. Don't wait until you're in the middle of a shipping channel during dense fog or grounded on a shoal with your family aboard to contemplate purchasing a piece of marine electronics with a chartplotting function. Besides, as stated above, a plotter of any decent quality makes navigating to your favorite fishing haunts much less labor-intensive.

Today's chartplotter has come a long way from conventional paper charts, often featuring a range of additional functions including man overboard markers, zoom abilities, overlays, and much more. Marine safety organizations and the United States Coast Guard recommend that boat owners continue to carry paper charts in case of power failure and as an additional source of navigational data.