Echopilot Forward Looking Sonar

[robavery]

Has anyone any practical info /experience on whether these units can see submerged objects, such as containers, when in deep water beyond the scope of the transducer? On reading the manuals it sounds as if once the transducer fails to get a return echo from the seabed the device sees nothing ahead.

 

[jamesjermain]

Echopilot specifically say that the forward looking sonar should not be relied on to see floating objects such as containers, though it might if you are lucky

 

[bedouin]

Irrespective of that I don't think you should rely on one of those to detect objects on/near the surface - it strikes me there is too much danger of interference caused by the waves for one to be a practical container (or whale) avoidance device

 

[Salty John]

The positive verdict on forward looking sonar in this months YM notwithstanding, I think they are pretty well worthless. I had an Interphase unit for three years while cruising the US eastern seaboard and the shallow waters of the Bahamas. I found that their vision is too limited, interpretation of the display difficult and, in answer to your question, their ability to see anything just under the surface at any distance ahead non-existant.

 

[robavery]

I would tend to agree with all said so far. It is just interesting that some folks I know have brought the kit primarily to avoid the likes of whales and containers. I am sure they work fine in confined depths but am yet to be convinced they give any comfort in the open ocean in avoiding such objects.

 

[trouville]

This is dreadful!! At £350 ive been saveing for one to look for rocks when sailing in the Baltic!! I though the price very fair compaired to the shock when running over or hitting a rock!(which ive done)

Now do i understand that a submerged rock might not be seen???And i was hopeing to have a good summer this year with one of these forward looking sonars!!!!

When im lost even with GPS i thought i could still choose a passage between submerged rocks haveing lost count of islands or bouys still see if i would be passing through a clear chanell or about to hear that dreadful terrifiying grinding noise!

 

[tome]

There's a huge problem with acoustic devices at near surface depths. The effect of local eg solar heating produces temperature inversion layers which play havoc with the acoustic paths and velocities (from which distances are calculated). A layer of warm surface sea will refract the acoustic beams and distort the readings.

A further complication arises due to near surface airation which can kill the beam or at the very least distort the return. The speed of sound in standard seawater is around 1500m/s. In air it is around 350m/s and the attenuation is much more marked

We use acoustics similar to an echo sounder to measure ranges between equipment at typically 6m depth in our survey work. Even at these depths, there are times when a combination of sea state and solar energy make it difficult to achieve a meaningful result. In shallow water (<10m), the effects are much worse

 

[alandee]

In deep sea the unit sees nothing. However in shallow water when travelling slowly the unit sees most things. We bought ours for motoring through the French canals, negotiating shallow marinas and berthing stern-to ( turn the transducer round for this) in med marinas. Saved our boat on one occasion. I would not expect to use it at sea. As the saying goes...it does exactly what it says on the tin!

 

[Steve Clayton]

[ QUOTE ]
...in shallow water when travelling slowly the unit sees most things. We bought ours for motoring through the French canals, negotiating shallow marinas..

[/ QUOTE ]
We have the FLS Bronze http://www.echopilot.com/products/forward_looking_sonar/fls_bronze.aspx
Bought it for nudging into unknown bays and shallow areas. 4 year old technology now but I wouldn't be without it.
Never thought it would be OK for looking ahead in deeper water for submerged bits and pieces (can't spell debrie).

www.seraph-sailing.com

 

[trouville]

Its the bronze i intend/ed to buy!!!! 4 vear old tech???? In the adds it looks fine for detecting shallows ahead????

Now what do i do?? Go ahead in the dingy with a lead?????I had so hoped this would end my dreadful and reasonalble fear of hitting rocks!!(not in the med though!)

 

[Steve Clayton]

[ QUOTE ]
In the adds it looks fine for detecting shallows ahead????

[/ QUOTE ]
Yes, in my opinion it is fine for seeing the seabed 25 to (almost) 100metres ahead. We would normally use it in both known and unknow shallows at 10metres depth and less to tell us the inclination of the seabed ahead. (getting away from what the original post was asking about in terms of submerged items not too far below the waterline in deeper water)

 

[trouville]

How or where did you fix your tranducer?Is it very large? I hoped to put it in place of the through hull log? Thats about 1 inch.

If i dont buy that i want a new SSB? I wonder if anyone uses it today??In anycase ill still have my old rig.

There dosent seem to be a lot of difference between the bronze silver and gold but the price,i had hoped Eagel or another would have brought one out for the boat show?? But they havent have they??

 

[alandee]

Further to my earlier post I hope I didn't put you off. As Steve Clayton stated I wouldn't be without it either. If mine broke down I would get it fixed asap. As I said it saved our boat once when entering a marina in a cross wind. Had I relied on the depth sounder it would have been to late. I guess its one of those items that once you have one you wonder how you ever lived without it. Bit like a boat really!

 

[Steve Clayton]

[ QUOTE ]
How or where did you fix your tranducer?Is it very large? I hoped to put it in place of the through hull log? Thats about 1 inch.

[/ QUOTE ]
Mine is fitted inline with the leading edge of the keel about 9" off the centre line on the starboard side.
Transducer specification is here: http://www.echopilot.com/cms/site/docs/FLS%20Bronze.pdf

 

[contessa26]

Sorry to be boring, technical and pedantic! But not withstanding temp inversion layers, speed of sound etc – from our experience – so far – of using an Echopilot Silver – I would agree with alandee and steve_clayton. Old technology now. But we like it! And use it a lot.

We use it a lot for trying to confirm depths ahead, at slow speed when entering rocky coves. Better than a normal echosounder that only tells you depth below – or after you’ve passed over the object – possibly too late. Like everything, you have to use it correctly, and know its limitations. And your limitations! Just like using a radar? Or a diagnostic ultrasound scanner!? Or driving a car. Or anything!

To answer the initial post – we specifically do not rely on it seeing submerged, or semi-submerged objects ahead.

Though funnily enough, our one works quite well in depths up to 40 metres or so, and at various speeds, but I’m told that perhaps we’ve just been lucky with the exact sighting of the transducer on the hull…

Best wishes.

 

[Gypsy]

I have an Echopilot Bronze and I confirm that it is unlikely to identify a floating object but it is much more useful than a standard sounder for assistance in shallow/shoal areas. It does take a bit of interpretation initially and gives false alarms in disturbed or cloudy water (depends on the reson for the cloudiness) but it does show the trend of the oceanbed, can be very useful when rounding land points to ensure you don't clip the underwater part and are great in anchorages or harbours to see how quickly they shallow or the depth at the jetty wall.

Not an answer to all needs but a useful tool as all other instruments are when used with care.
Ray

 

[Gazza]

I've had the Echopilot with professional transducer on two boats now,and wouldn't be without it. As other people have said, not much use for detecting objects, but extremely useful for slowly creeping into strange anchorages or marinas. Saved me on one occasion when going into an anchorage in Ireland when the transit wasn't visible and the sounder picked up rocks over 100 metres ahead.
On the downside, the distance ahead is governed by the depth of water, and I've turned the shallow alarm off as it is extremely sensitive to almost anything ahead, hard or not.
Overall, a good piece of kit.

 

[jonic]

ROB!!!!!!!!!!!!!!!!!!! I've told you a thousand times I wouldn't be without mine, now others who have actually got one have said the same. Go and buy a bronze and then buy me lunch. You'll love it when you start anchoring around the med.

see you next week /forums/images/graemlins/grin.gif

 

[Ariadne]

We have the platinum version, as previously posted it does what it says on the box. We use it for creeping in and out of places (with 7' draft you have too), wouldn't be without it.

It will not scan ahead for submerged objects, but then it does say this in the instruction book.
May I suggest you use the Mk 1 eyeball and gut instinct for this-much more effective. Still the Echopilot is a good piece of kit I have no complaints.