HOME Catching up with fish Grouper vol.2
Catching up with fish
What can we learn from this fish finder screen?
I slowly follow the fishing spots I have saved on my GPS system and start recording my screen. The data displayed on the fish finder are obtained thanks to the use of both 50 kHz and 200 kHz ultrasonic waves.
The image is a screenshot taken as I approached the fishing spot where I caught Grouper by SLJ (Super Light Jigging).
The Grouper feed mainly on shrimp, crabs and other crustaceans and small fish. Therefore, Grouper can be found near rocks and other similar steep terrain that form the perfect habitat for their preys. On the screen, we can notice the presence of Grouper echoes above the rocks, but when observing them while diving, we notice that they also occupy the spaces between the rocks.
It is possible that they took refuge between the rocks because they got scared when they saw the diver.
It is known that Grouper are even more cautious than rockfish who occupy the same kind of place.
It's fairly easy for our fish finder to catch echoes of fish swiming right above the rocks, but it's much harder to detect these fish as they move between the rocks.
This is because ultrasounds, being ultra-sensitive, are easily reverberated by any obstacle that crosses their propagation route such as the surrounding rocky outcrops and steep reliefs.
For these reasons, it is recommended not to look directly for the Grouper, which are very difficult to spot, but rather to look for the kind of place they are hunting small fish and crustaceans. Until you find your first fish, it is better to look for the area rather than looking for the fish itself and for this reason you should sail very slowly.
DAIWA field tester, Writer at Boat Club, a monthly Japanese boating publication
Nobuaki is a hobby angler who travels around Japan together with his beloved car-top boat Tomoe-maru. With a keen interest in fishing as well as scuba diving, he has gained a substantial amount of knowledge in how to utilize fish finders to the fullest. Nobuaki regularly holds well-attended training courses in the use of fish finders, as well as being a proponent for proper sea manners and safety at sea. Sharing his knowledge is a passion for Nobuaki, and he manages his own homepage as well as being a sought after writer in Japanese boating publications.