depth finders

As I am planning to have a look around Earls Court next week I
was wondering about the merits of transom mounted transducers
for depth finders.Do they work only when going slow or stopped?
Is the unit at the transom very delicate I don't want to start drilling anything too much.Comments please when you get a chance.

mccabe

I have had transom mounted transducers in the past that have worked fine around 35knots. If your jumping around they can get confused but should work fine otherwise.

Regards

Mark

I have had experience of both transom mounted and through hull. Both work well if fitted correctly. The transum mounted version is the easiest to fit as you don't have to worry about creating a zero bubble medium between the hull and transducer, and you don't have to worry about what materials are in the hull which could cause noise or even no signal return.

However at speed as soon as air gets under the hull around the transducer you will loose the bottom. Also at spead you will loose the signal return. If you transom mount the transducer, also be aware of placing it where you could snag when launching and recovering.

I have just returned from Earls Court and there are heaps of electronics. I suggest you talk directly to the dealers, they have been of great help to me today.

Andy

with drilling any holes

I use the attached piranha fish finder which is superbly simple and even tells you water temperature

http://www.humminbird.com/hb_Products.asp?ID=224

Cannot make any particular recommendation, but have used several cheapish models over the years, all of which have worked well

The depth alarms seem a bit of a waste of time as they are difficult to hear with a noisy engine, but good for river work pottering along,excellent for coming in to a beach as at slow speed they are accurate, can save a prop

run the lines over the transom, mounting of sender is crucial for good signal must be as much out of disturbed flow, instructions will tell you where

should only require a couple of tiny pilot guide drills and then the small sender unit will be attached to transom with stainless selftappers- so no actual holes in transom required

excellent piece of kit a must for our murky waters, at speed you should obviously rely on charts as a depth sounder is useless if it gets shallow quickly

going to the boat show towards the end would probably be better for a bargain

search www.loot.com and type in garmin or hummingbird etc, I picked up a new one for 50 quid once

Our local fast fishing boats mount theirs inside the hull cos they are landing on exposed beaches with possible damage. When I had one it was just mounted in the drain well at the transom on the bracket supplied for outside use, fairy hard down onto the grp and we just slung pint of seawater in there when we launched off the beach(if it was rough this process was fully automatic!). On the Humber the transducer is bonded down onto the glass in the drainwell. We used silicone for this -totally contrary to instructions but the method used by the fishing lads who say they can remove it easily if selling boat. The silicone is not a recommended medium as it absorbs signal power but we have had no problems with this. The sounder is fine until we trim out and the water aerates under the mounting site then you lose it until you trim down again

Used a Eagle fish finder with transom mounted transducer for the past four years on an Avon Rib.


If the sea chopped up you would loose the bottom as the boat bounced out of the water, (to be expected I think)

I would have to tighten the transducer mount every know and then to stop it swivleing up to when in use as opposed to when you wanted to beach or recover the boat.

Just remeber to swivel it up before recovery and you should be fine.

Currently got an antique Humminbird (in about it's fifth boat). Before I transom mounted it I flung it in the drainer well which always has an inch or two of water in it. It's now screwed to the front of said well, no prblems with 35 knots, grounding, trailers, holes in the hul.