Side reading sonar

[Tonyr]

I am thinking of upgrading from a dual beam Humminbird fishfinder to one of their (much more expensive) side reading products. My interest is in the claimed much improved 3D picture/display of the bottom and objects on it.

The environment is fresh water, depth 10 to 100 feet. Any experience or opinions? No-one else seems to offer anything affordable with this capability.

Thanks, Tony.

[gregleeber]

Hey this is a great question: Allow me to axe a more encompassing (get it en-compassing... ha ha) question:

I've been thinking about sonar for my Milky Way. I use her in the ocean but off the Maine coast so I want to see all those ledges that would reek havok. Would this work for my applicatioin and can I piont them forward to get a view of what is in front of me and to the sides?

[Tonyr]

Bump. Anyone?

Tony

[redbopeep]

We cannot speak to it's utility because we've not launched the boat yet--but we did just drill the holes in the hull for the two transducers (and cut the faring blocks to fit the hull) for the Interphase SE200C forward looking sonar that we bought this summer for the boat. (product link) The unit shows forward ("forward looking sonar") and to the sides as well as down. Its scan is 180 degrees. The prices vary widely via online vendors, so research where you can get it and get several bids.

We've heard mixed reviews from others who own the same product. We've heard the particular FLS we bought is good for rocky bottoms or bottoms with ledges/uneven terrain as well as for slower moving vessels (like sailboats) and is not so good for keeping one off sandbars (shallow bottom coming up slowly) or fast planing hulls.

We've heard there's a learning curve and you has to become familiar with what you are seeing on the display--else you'll be having a heart attack every little bit when you think you're about to ram an unknown sea wall that actually ISN'T there. Some folks can't ever figure it out and thus its a waste of money for them.

We also know some folks whose units display so much noise that they state they NEVER see a good bottom signal--we're suspecting that the transducers on their hull were installed way to close to the keel or too far forward on the hull so they're prone to water turbulence causing interfering signals.

Where it is installed and how carefully one aligns the two transducers (for those that have two transducers) is pretty key to the performance. If you have a full keel boat (like us) the two sensor variety makes sense (else you're mounting a transducer through a couple feet of forekeel...) and mounting them as close to the keel as possible w/o having turbulence from the keel interfere with signals is the goal.

Will let you know how we like ours after our relaunch this fall

[jerry bark]

a good friend of mine had one on his fishing boat. his review: it works good and is cool, but he did not find it useful for his kind of fishing.

if you are concerned about hitting ledges consider that you will have very limited warning of an approaching ledge from one of these. I do not know what there angular range of view is but i would be concerned that once i saw the ledge I would be too close to miss it anyway. some experimentation will be in order. In any case I think the best you can hope for is to "see" an abrupt change in bottom contour at a distance equal to ~1.4 times the depth of the water you are in.

for that type of purpose have you considered getting a good gps with contour mapping of your sailing area? even though gps data has inherent inaccuracies as well, the one advantage you will have is the ability to zoom in and out on your chart. I love being able to zoom in to a 1/4 mile scale for following the channel into the boat ramp while i can use a 10 mile scale for navigating to a fishing spot.

good luck
jerry

[redbopeep]

a good friend of mine had one on his fishing boat. his review: it works good and is cool, but he did not find it useful for his kind of fishing.

if you are concerned about hitting ledges consider that you will have very limited warning of an approaching ledge from one of these. I do not know what there angular range of view is but i would be concerned that once i saw the ledge I would be too close to miss it anyway. some experimentation will be in order. In any case I think the best you can hope for is to "see" an abrupt change in bottom contour at a distance equal to ~1.4 times the depth of the water you are in.

for that type of purpose have you considered getting a good gps with contour mapping of your sailing area? even though gps data has inherent inaccuracies as well, the one advantage you will have is the ability to zoom in and out on your chart. I love being able to zoom in to a 1/4 mile scale for following the channel into the boat ramp while i can use a 10 mile scale for navigating to a fishing spot.

good luck
jerry

Actually, the folks I know who LOVE their Interphase use it in high latitude sailing where the charts aren't so great, GPS "contour"...ummm. yea, right... and the GPS datum isn't so great either. They routinely see rocks, boulders, ledges and such as they explore small inlets and bays. That is exactly the sort of thing the FLS is best for. Yea, if you're in 8 feet of water, you're screwed unless you're moving very slowly so you'll have more time to react to the info.

[Tonyr]

Thanks for all the helpful comments. I am still undecided. Perhaps this winter's boat shows will offer an opportunity to learn more. If that works out, I will post here.

Tony.

[redbopeep]

Good luck Tony. When we re-launch (next month or so), I'll let you know how the Interphase works.

[Flying Orca]

My dad might have some thoughts, he used side-scanning sonar for polar cod schools on a research vessel in the Northwest Passage. I'll drop him an e-mail.

(later: he says "no opinion" - sorry!)

[mikemitchell]

seems to me in theory anyway that a normal transducer pointed in the right direction would display anything in the beams path. Course then you lose the depth function replaced by distance to object. Currently setting up my kayak to try this but no time till Feb

[Gary E]

Here's a picture you want to see when your fishing..



There are systems that look ahead and to the sides... all it takes is more money..

[JOBBER]

This website is a bass boat forum. This thread has a bunch of actual screen shots of a Humminbird fishfinder side scan sonar. They may provide some insight.
http://bbcboards.zeroforum.com/zerothread/227957

[Tylerdurden]

If you scan the commercial rags sometimes real sonars show up.
Guy in Portland has one he got from one of the big treasure hunters when they upgraded. Its pretty sick seeing lobster traps and barrels slide by.

[SV Papillon]

Not to be a nay sayer, but..... Having spent the last 12 years on boats 200-350' that fish excluseivly by sonar, I would be dubious of the accuracy and use of a sonar side scanning etc on a small boat. We have 4 down sounders of various freq and a forward scanning sonar, the pictures all vary, reading them is a interpretive science that the guys fishing take along time to figure out, they also run $50,000 and up to $150,000 a piece. Much like the color radar displays and plotters of late, just because there is a highly defined pic on your display doesn't mean that is what's going on. The other point on side and forward scanning sonar is it is extremely susceptible to motion, IE rolling around. Unless it was flat calm out you would not be able to make heads or tails of what you were looking at. Having a depth sounder transducer mounted at a forward angle would be a nice addition to the standard one for seeing the bottom come up, but practical? How fast do you run through un charted waters? my 2 cents
Jake