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Wallrat · 07-06-2007, 18:56

What do you guys think about the fwd-facing sonars out there? I was looking at the Interphase site and it seems like an awful lot of clutter in the demo videos. I imagine there's a gain option that you might be able to use to tone that down but then range would suffer. I dunno...seems like a good idea for avoiding hazards - rocks, coralheads, whales, shipping containers. But then it also seems like the technology isn't quite there yet.

CSY Man · 07-06-2007, 19:05

The US Navy likes 'em...

Never tried one in real life, but the idea is good.
Hook it up to a computer and an alarm and you should have a couple of minuttes warning before you loose your boat.

Or just pay attention.

Human performance what it is, probably a good idea in the long run.
We all screw up..Sooner or later.

DeepFrz · 07-06-2007, 19:25

Just read an article by Andy O'Grady and I think they are okay for probing small areas. Such as checking out and anchorage, or feeling your way into a poorly charted bay. He travels the higher latitudes so he thought his worthwhile, but it takes a lot of practice to become proficient with them. They also have a slow refresh rate which can be confusing. Apparently setting the alarms is a problem.

His article is in Ocean Navigator and I had the same feeling. Not quite there yet, unless you are messing about in the high lattitudes.

Intentional Drifter · 07-06-2007, 20:45

I've been interested in them and reading what I could find, including the Ocean Navigator article. The synopsis of what I've gathered:

After you get enough experience to interpret what you are seeing, they can be very helpful for quickly charting out an unfamiliar anchorage, as well as finding a passage through poorly charted and unknown tight spots, so long as you can go slowly and don't have too much wave action. They are not much use as a warning system for floating or partially submerged hazards, as the signal noise close to the surface and limited range likely wouldn't give you much warning and/or you would have to use so much sensitivity that you would get many false alarms.

Of course, for the prices of the ones we could reasonably call within the usual cruiser's budget, this might be enough usefulness to justify them. Like with almost anything, if you're willing to pay more -- like $50 to $60K, then you can get a much more capable system.

Or, be in the right place at the right time when the Navy is surplusing one -- but, then again, that might be a bit heavy for our boats.

ID

Latitude9.5 · 07-06-2007, 22:01

i have an interphase but havent installed it yet, will be installed in 2 weeks, so I will let you know after i scan the inlet LOL

44'cruisingcat · 08-06-2007, 00:38

We've had an echopilot FLS since 2000. It doesn't do the side scan like the latest Interphase sonars, but scans forward in an arc from vertically down to horizontally forward. It also doesn't have a colour display. But they only cost around 1/2 what Interphase do, the update rate on the display is very good and overall mine works very well.

I doubt it would be much use as far as spotting shipping containers is concerned, until you were quite close anyway, but it is excellent for spotting reefs, especially coral, which can tend to be a vertical wall.

Usually it can "see" forward by 4 times the water's depth, up to a max of 150m. There is a more pricey version now that looks 200m forward.

Also their transducers fit in std 38mm thru-hulls, and can be withdrawn and cleaned, while the boat is in the water, which is a plus. The interphase transducer is quite large, probably not suitable for a fast multihull.

Here's their website: home :: Forward Looking Sonar by EchoPilot

Charlie · 08-06-2007, 08:06

CC:

That forward looking sonar looks great. Which one do you have? I can see where it would save hitting a few rocks or coral heads and pay for itself quickly.

Cruisingdad · 08-06-2007, 09:07

It is my understanding that the interphase has little to no use in less than 20 feet of water. That is per Interphase. I was going to get one keep from running aground, but they said that was not its best use. Call their tech line first.

- CD

DeepFrz · 08-06-2007, 09:46

Charlie, the biggest problem(?) I see with the Echopilot is that it has only a vertical scan. It would be hard to tell if what you are seeing is a rock or a wall. The Interphase has both vertical and horizontal scanning which allows you to see the channel. A rock off to your side would show up as a rock, a shelf or wall would also show up as such.

I don't understand the CruisingDad's comment. The main use of forward looking sonar is to help keep you from running into things, mostly the bottom.

Just my opinion...

Cruisingdad · 08-06-2007, 11:32

Deepfrz,

I did not understand it either (well, their comment). When I was cruising SW Florida, we were ALWAYS running aground (as many of you can guess that have been there). THus, we decided to look into a FF Sonar (specifically the Interphase) to find the channel.

Interphase told us, contrary to what has been writte up previously, that their product is not very effective in less than 20 feet of water. I asked him its purpose then, and he said to see floating objects, like shipping containers?? That statment goes against what has been stated earlier in the thread. Thus, we elected against the product.

I guess the product would be beneficial in areas where you have "deep water" and rising coral heads, etc. Unless the tech guru at Interphase was incorrect (which is very possible), it would be useless areas such as SW Florida and Keys where the water is very shallow. As many may know, in SW Fl, Keys, and Bahamas, if you show 20 feet of water you are certain the depth meter is broken!!

Again, I am giving you what I WAS TOLD, not my direct experience. I hope I am being clear about that. Just check with them first. If the info given to me was incorrect, I would be interested in investing in the product too. But won't Sea Tow be dissapointed (smile).

- CD

DeepFrz · 08-06-2007, 13:20

CD, thanks for the explanation. I just didn't understand what you were saying in previous post. Was your contact with Interphase recent, or some years ago?

Cruisingdad · 08-06-2007, 14:25

ABout a year ago, I think. Maybe two.

- CD

44'cruisingcat · 09-06-2007, 15:00

Charlie ,we have an Echopilot Compact FLS, which is no longer made. From the website I would say the "Silver" one supercedes it. (It looks just the same)

CD, as I said before, the sonar can see forward by around 4 times the water's depth. (which would agree with what Interphase have said) So if your'e in only 2m of water, it's barely going to see past your bows. BUT this can still be useful, you can make turns left and right and find deeper water. That would probably be a little easier with the interphase, with the side-scanning feature. The main thing in really shallow water is to slow right down, so you have time to react to the info the sonar is giving you.

But really they work better in keeping you off sharply rising rocks, than in preventing groundings in shallow sandy bottomed water, where the bottom contours are more gradual.

Deepfrz, your point about it being hard to tell whether it was a rock or a wall in front is fair enough, but does it really matter? The main thing is, it's in front of you - you wouldn't know it was there at all, with a normal sonar. Obviously what you would do when you see the bottom rising sharply is change course - if it's an isolated rock you will see the path ahead becoming clear, if not, you keep turning.

One surprising use for it that we have found, is that you can actually watch the anchor, both going down or coming up. You can see when it hits bottom, and then let the boat settle back to pay out chain, and you can also see when it pulls free of the bottom, so you know when you have to start to keep an eye on your position in a tight spot.

Overall, we have been happy with the unit, and we definitely want one in the new boat.