Why Can’t I Rely on GPS Alone on Extended Cruising Trips?
Alternate title – GPS; Siren Song to Unprepared Navigators
By Capt. Joan Gilmore
Have you heard the story of the Swedish couple cruising the Mediterranean, who mistakenly typed “Capra” into their GPS, when they actually intended to go to the island of Capri? They arrived safely at the island of Caprai, over 300 miles north of their goal, only learning of their mistake after they had docked and were exploring the town.
My own cautionary tale unfolded while departing a dock in Puerto Vallarta. Our captain quite suddenly started casting off lines without orders to secure hatches or gear. As we left the dock a large wave crashed over the top of the cabin, drowning the navigation laptop directly below the open hatch above the nav station. We were forced to navigate peacefully and serenely without electronics up the coast to Cabo San Lucas, using our paper charts.
Other reasons to maintain paper charts include …
- giving your location and coordinates to rescuers in an emergency.
- being able to read where underwater shoals and submerged objects are; these may not be shown on GPS, depending on your software.
- also, just being able to give your crew the big picture of your entire voyage in a tactile and permanent format.
GPS is a wonderful invention, embodying the Siren’s song to many new sailors, promising easy access to adventure. Just make sure that you are the prepared master of your navigation, and not an unprepared victim.