March 6, 2020 — According to legend, the term “crow’s nest” derives from the practice of Viking sailors, who carried crows or ravens in a cage secured to the top of the mast. In cases of poor visibility, a crow was released, and the navigator plotted a course corresponding to the bird’s flight path, which invariably headed toward the nearest land. If the bird didn’t return, it was a sign that land was near. The Bible also tells us that while on the ark, Noah released a raven first, and then doves, to find dry land.
Sailing vessels used a crow’s nest as a vantage point to spot other ships, hazards, land or, in the case of fishing ships, fish schools near the surface, long before radar was invented. Fishermen have always relied on the understanding of the elements to guide them: the water current, its temperature, the direction of the wind and its humidity are important information used to locate fish. Now, drones are bringing some fishfinding technology back above the water.
Modern times have given fishermen new tools to search for fish schools, from the radar or sonar to GPS. Fish shoal and school together because large numbers gives them some kind of protection against some of their natural predators. The same critical mass that provides the safety of numbers also makes them easier to spot.
Drones make it more accessible to search for large quantities of fish or in some cases, large fish. While owners of bigger offshore fishing boats may have the economic means to use technologies like multibeam echosounders, small-boat operators may find that drones are an affordable solution to spot fish schools. Raymarine’s Axiom UAV application is a good example of such a solution, as it brings together the power of advanced marine electronics and advanced unmanned aerial vehicles.