Had a PM from another member thought I'd post the info I sent him as others may find it useful.

Info is specific to a Lowarance HDS but generally applies to all sounders

1.   Transducer is where most problems lie (I’ll stick to Transom Mounts), you need to make sure this is set up properly first.  Location and angle are where most problems are made.  The manual will show how this should be done better than I can. 

In short though the centre line of the transducer (looking from behind) should be aligned with the bottom of the hull (at the point where the transducer is mounted).  On some hulls it can be slightly higher but not to the point that the bottom of the transducer is higher than the bottom of the hull.  It should not be angled forwards on backwards (you can get away with a tiny bit of forward tilt but not backwards.).

It needs to be where there is no turbulence (aerated water) coming off the hull (strakes, bumps, damage or repairs to the hull will cause turbulence) and at least one foot from the motor.  It your sounder works well in calm water when stationary but is a problem underway hang over the back whilst someone else is driving and check the transducer is running through clean water (green or blue as opposed to full of bubbles).

Mono hulls are easy to fit in this regards but cats are harder to find a good spot as turbulence comes out from between the hulls –

2.  Transducer cable should be run on the opposite side of the boat to electrical wiring and radio antenna cables (though these days they are shielded pretty well).

3.  On the transducer cable where it plugs into the back of the screen there is a sliver sticker with the transducer code you need to set this into the unit (in settings or setup somewhere) so it is set up for your specific transducer.

4. Push menu twice then select sonar then fishing mode  -  set it for the type of water your fishing and press enter (salt water up to 60 feet will be the shallow water setting otherwise use the deep water setting).

Turn fish ID off (this is a non negotiable – you will get to know your sounder better without it)

Manual settings will give the best returns.  Turn auto settings off.

Set your colour line to around 75%

Set sensitivity to 70%

Scroll speed - set to medium as a starter (can go higher depending on your boat speed – higher settings will show more detail (regardless of boat speed) but stay on screen for less time)

Set the depth range for the depth you are in + 2-5 metres (this depends on the depth variances where you are and you may need to adjust the extra to suit so you don’t have to adjust it every 2 minutes if in large variances of depth).  You can get your screen to show more detail by setting a top and bottom range such as only looking at the depths between 30-50m in 45 metres of water

Noise reduction – set to low

Ping speed set to around 10-15 (higher ping speed (pulse rate) at faster speeds if needed)

Surface clutter - set to low.

The above should settings should be generally right.  Now turn up the sensitivity until the screen is over cluttered and full of noise - Then slowly turn it back down until you just have a small amount of clutter mostly towards the surface. With some clutter towards the surface and just the odd spot here and there near the bottom your sounder should be set pretty well (when seeking fish in the mid to bottom ranges). - If looking for surface fish look over the side of the boat.

If you now go into shallower water you will need to adjust the sensitivity down if deeper adjust it up.  Also if you go into water (say a river or estuary) with more sediment you will need to turn it down and vise-versa when going back out into cleaner water

If getting too much clutter on your screen this is usually one of three things

Turbulence – if this is the problem it will be clear when stationary and worsen when underway.

Other two are  – your ping speed is too high or your sensitivity is too high – check both most likely sensitivity but too high a ping speed can have the same result.

Cheers Paul