This dual use not only pinpoints bottoms likely to hold fish, but simultaneously shows where a boat is positioned on a local chart thanks to the miracle of the Global Position System (GPS).

In this age of electronic navigation where GPS course plotters ... Deviation is different on every boat; however, the compass can be adjusted for deviation. Nautical charts are like road maps ...

GPS data from Guma Aguiar's boat indicates he could have boarded another boat. July 13, 2012 — -- Deepening the mystery of missing millionaire Guma Aguiar's disappearance, experts examining ...