Thanks for this Forum.
I am looking for advice on mounting the transducer for a Humminbird Helix 7 Mega SI GPS G3 on an 18ft Bowrider with Mercury 4.3L I/O. Has anyone done this successfully on such a boat? Photos of your installation would be very helpful. I don’t want to buy this Sonar without some idea of how useful it will be.
My application is to look for interesting places to dive on with my ROV.
The Helix Series Operations Manual and the Getting Started manual say nothing about mounting the transducer. That information is in the Transducer Resource Guide.
The manuals can be found here:
https://www.humminbird.com/support/manualsScroll down to Transducer Manuals to find the Resource Guide.
Page 7 of the Helix Series Operations Manual has a useful list of Humminbird models.
Page 256 tells you which transducer is used for the Helix 7 Mega SI GPS G3.
The Helix manual is annoying because it covers all the different models and many of the 330 pages apply to other models. Apparently no one provides nice manuals suitable to carry with the devices. Depth sounders and video cameras, for example, are too complicated to use without a manual but then you have to carry them. Printing a copy winds up with a sizeable binder. Staples will punch the pages for a spiral binding with cover sheets that is the best to be expected. A manual on a ‘phone is useless in my opinion. I don’t know if it is on the Sonar but I suspect not.
I gather the Side Imaging is best used at slow (< 5 mph) speeds.
I am considering mounting the transducer beside the hull drain hole at the bottom of the V hull. It would be 8” from the front of the lower unit and 24” from the center of the prop. Has anyone tried this? I don’t want to start drilling holes to find out it does not work here. It could also be mounted further away toward the Chine but I’m not sure how much of the hull would be seen. The beam may be narrow but it will not be perfect enough to shoot through the 8” gap without scattering off the hull and lower unit.
Another option is to mount a simple Depth Sounder (Down imaging Fishfinder) in the boat and deploy the Sidescan transducer on a long arm, well away from the boat, to be used at slow speeds. i.e. two different Sonars.
I am fitting my ROV with the BlueRobotics Scanning Sonar for collision avoidance and to navigate close enough for the camera to be useful.