Switching Transducers.

[Nasher]

After nearly running aground approaching Priory Bay IOW at low tide yesterday I’ve again been pondering the old issue of Fishfinder/depth transducers mounted on the transom or within the hull, but at the stern so they work at speed.

My Transom mounted transducer works well at all speeds, but of course approaching a beach at very slow speed, the hull is in the water probably 5 or 6M ahead of the transducer.

I’ve been thinking about adding another transducer bonded inside the hull near the bow, but far enough back that it’s below the water line at less than 10 knots. I then need to find a way of switching between the two.

I presume I’ll need to make up a connector that both transducers can plug into, and that also contains a multi-pole switch to break contact with one transducer before connecting the other.

Judging by previous experience with the Garmin call centre technical staff, they will probably just tell me to unplug one and plug in the other each time!

Has anybody tried this? Or have any ideas?

Nasher.

[Jizm]

try RS for a multipole changeover switch that may do the job.

RS

Jiz

[Jizm]

something like stock number:

340-308 (3 pole changeover switch)

Jiz

[Stuart M]

Assuming you had the depth gauge at the very front of the boat (impractical) I would have thought if you are travelling at any speed you couldn't stop the boat in its own length (i.e. given the boat speed and your reaction time). So you'd still hit the bottom!

Usually if you are in deepish water the only obstructions are marked on a map or in publications like solent hazards. If you are in shallow water then take it slowly and lift your engine slightly. Everyone one knows that approaching a beach the depth of water usually gets shallower! Looking at other peoples position, people in the water and the water usually give a good idea. Also a fish finder will usually tell you is beneath you: sand, rocks. mud etc

Given the depth of your prop you should be able to see the ground approaching in all but the lowest visibility water.

I mounted mine in the hull using Isopon P38 and it works fine.

[Bilge Rat]

What you need is a forward facing transducer, not sure who makes them but there is one on the market that beams out in front of the boat, this way you can see shallow water or obstructions coming earlier.

[pettal]

http://www.echopilot.com/infopage.asp?infoid=145

That's what you need and the lower versions aren't as horrendously expensive as you might think.

[Swifty]

Look guys, keep it simple. To find the depth while approaching a beach or shoal use the paddle. It works so well even a dipstick can use it.

When your echo sounder reads 1.5 metres or less then the water is most likely 2 metres deep (cos the sensor is on the keel) which is enough for a paddle.

Simple.

[Simon B]

You could buy on those cheap as chips Eagle cudas and glue the transducer in place in hull and simply have two screens.