Finally got a clear picture at speed - FCV620

[Dignity]

Marto, had another thought, I would put a vertical groove in the inner tube so that the wing nut bolt would lock into this groove (would prefer 2 wing nutted bolts) this way if the inner tube slipped/loosened then the transducer wouldn't spin around and cause damage to the cable. This would depend on the gauge of the inner tube and whether it was viable, if there is no thickness there then I would definitley go for an extra wing nut. I may be a security nut but as I can't afford one of those transducers at the moment I would look at protecting it as much as possible. I do like the protection you gave to the front with the angled bracket.

[marto78]

The angled bracket at the front wasn't so much for protection but to reduce drag in the water, a home made bracket I tested earlier had that much drag that it was acting like a trim tab and lifting the stern of the boat up on that side.
I found the best way to get it straight was to be doing about six knots when lowering it and it sort of alligns itself.

When I get some time I may look at making up a pin or something to lock it in the down position so that it has no chance of moving anywhere.

Thanks for the ideas Dignity I will definetly be putting in that bolt at the top to stop it falling out.

Marto