Why Use Deep Drop Lights?
Deep drop lights are used to attract fish that inhabit depth of 300ft and below such as yellow eyes, tile fish, swordfish, escolar, groupers, snappers, etc. The theory behind deep drop lights is to imitate bioluminescent prey.
At sea, the color spectrum dissipates underwater of approximately:
Red - 15 feet
Orange - 30 feet
Yellow - 65 feet
Green - 98 feet
Blue - 197 feet
The portion of water that carries sufficient sunlight to support photosynthesis is called the euphotic (daylight) zone. Below this, where light beings to fade, is the disphotic (twilight) zone. The twilight zone ranges from 650ft to 3,500ft and is a deep blue-green pigment as sunlight diminishes. Thriving in this range of depth are all forms of bioluminescent marine life such as fish, squid, jellyfish, krill, etc. (See video below of a squid changing color)
Deep Drop Light:
The best deep drop lights are those with rigid exterior that will not implode easily. Over the years cylume sticks have been replaced with battery operated deep drop lights, and even more recently, water activated deep drop lights. These lights can withstand the water pressure around 2,000ft. The newest water active lights, such as the Gotcha BiteLite and the Mega Gotcha BiteLite, have an internal battery pack and are solidly encased allowing them to withstand water pressure down to 3,000ft.
The best deep drop light color is still a matter of preference. There is no evidence that suggest that any color or color combination has a better effect in the deep. But given that each color is carried by a different wavelength, perhaps this is why most fishermen prefer a flashing RGB (red, green, blue or disco) light combination. The red provides a longer wavelength that dissipates quickly where the green is a shorter wavelength with less dissipation while the blue is an even shorter wavelength with an intense pulse. But overall, color is the angler’s preference as success has been reported on all solid and color combinations over time.
Names for Sword Fish by Region:
Spanish - Emperador , Italian - Pesce Spade , Portuguese - Espada, Espadarte , French - Espadon, Russian - Meda, Japanese - Mekajiki
Rigging a Gotcha BiteLite in a Squid.
Sword Fish Geography:
Sword fish can be found the waters of the Pacific, Atlantic and Indian Oceans and typically residing in the range of 650-2,000ft, although it is believed they can swim to much greater depth. They can withstand temperatures from 40 to 80 degrees Fahrenheit. This fish adapts to the cold by isolating the heat in its body to maintain its brain temperature warm in the frigid depths.
Sword Fish Squid Rigging without a Light