Gear ratio – The number of times that the spool of a reel rotates while the handle is rotated once.
Gemini lead – A type of grip lead where the wires are housed in a detachable plastic nose cone.
Gill arch – The structure behind the gill covers of a bony fish (or within the gill slits of a cartilaginous fish) that supports the gills.
Gill filaments – The parts of a fish’s gills that absorb oxygen from the water.
Gilling – A boat fishing style where a bait or lure is fished on a long, flowing trace fished off a boom. The rig is lowered to the bottom and retrieved back towards the surface. Also known as slow retrieving
Gimbal – A cup which is able to move in three dimensions and seats the butt of the rod when big-game fishing. It may be fitted on a butt pad or a fighting chair.
GPS – Short for Global Positioning System, a satellite navigational system extensively used in the marine environment on commercial and recreational boats. Allows the angler to locate or revisit prolific marks in conjunction with a fishfinder.