Transducer losing the bottom in rough seas

S

Sarge

New member
Hello All,

I wrote about a recent adventure in rough seas in my blog http://theseabadger.wordpress.com/ but what I didn't write about was losing the bottom while I was travelling.

Summary: I took my boat out yesterday in 30+ mph sustained winds. It was a wild ride. I was in the Puget Sound in waters approaching 1,000' deep. The waves were easily 3-4' high and in very short intervals...maybe 2-3 seconds (that's a guess). I have a Garmin 740s with a Garmin transom mount transducer. Normally the transducer does very well until it is not knocked out of position from a big wave or debris (it is mounted too low and needs to be adjusted). This time she was reading to 650+ feet at 16 kts in this crazy water, but then she lost the bottom and never found it again. I thought the transducer had been pushed up by the force of the waves, but when I took the boat out of the water it was in the correct position.

I realize that this is a very generic kind of question, but is it pretty normal to lose the bottom when you're being bounced around in the kind of water I was experiencing?

When I first entered the marina on my return, I noticed that it was still blinking at 654' and hadn't read the bottom. To be perfectly honest, once in the marina the wind was blowing so hard and making the boat crab at a 20-25% angle, I knew it was high tide so I never looked at it again to see if it did find the bottom. I was just trying to keep from hitting other boats.

I've been very happy with the Garmin combo (GPS/transducer) and this is the first time it lost bottom without being knocked out of place, so I'm curious.

As always, thank you in advance,
 
We have the same setup and we also will loose depth in rough conditions but it does always come back once things smooth out again dispelling my fear that debris in the water ripped it off. How fast does it come back? Ours takes a bit longer (couple of minutes) while moving and seems to return to normal sooner if we are moving very slow. There may be a way to reset it while powered on but I have not looked for it yet. Glad the boat performed well for you.

We were out and travelling against the wind from Coupeville to Port Orchard during the last small craft advisory but we were going a bit slower than you most of the time. We did ride up over a really impressive. 9-10ft wake coming off a freighter headed south along side our boat perpendicular to the wind waves. It was the first wake I have seen that size and must have been a combo of the 5ft + wind waves and the boat movement against it. Cindie thought we were toast but I knew it was just another wave to Aurelia and we bobbed right over it.
 
The depth sounder on our boat quit working in deep water and, as always, the first thing checked was the connections. No dice. While fooling around with the unit (Garmin 4210) I selected 'automatic' on the sonar calibration page. Problem solved! Somehow the unit needed a prompt or the calibration reset.
Dunno if it's related but once, checking the unit before a trip, the GPS would seemingly not function. Turned out the chart scale was so large no details showed. This is something the unit did on it's own. Something similar happened to the RADAR at the same time.
 
Greg and Chester,

Thanks for the feedback. I'll have to look into the "automatic" setting to see if that helps, or the power down/ power up option.

I do really like the system.
 
We've had 4 different Garmin plotter/sonar combo units on 3 different boats and have had that same issue with every one when it gets a bit rough. I just stop and the depth comes back in a few seconds. Transducers were all mounted properly. I love the Garmin plotters, I think they are fantastic... the easiest and most user friendly of the brands I've played with, but their sonar sucks, IMHO. I'd like to eventually get a stand alone Lowrance unit since we use the boat for fishing 99.9% of the time. Even a cursory glance at the bass boat community will show that Lowrance is so far out in front as the overwhelming choice that there isn't even a second place. Those guys are serious about their sonar and the information that you see on the screen is way better than Garmin will ever hope to be.

Also, we've had wonderful experience with Garmin customer service.

Rick
 
Sarge - I have a Garmin 3205 chart plotter with a transom mount transducer. Many months ago it started getting erratic reading the bottom. Then it would quit at times but if restarted the chart plotter it would be OK the rest of the day. This went on for months then it eventually quit working completely. I updated the software for the 3205 and the transducer has been working perfectly since then. Check on-line for an update for your 740s. If there is an update, it may fix your problem.

Dave dlt.gif
www.marinautboats.com
 
Brent,

I haven't had the opportunity to get on the boat again since. I will definitely try changing the frequencies if she's still not finding the bottom. I hope that the off/on (as in putting the boat away in its rack) will reset everything, but if it doesn't or continues to have a problem I'll be sure to run through these suggestions.

thanks
 
Hi Karl,

I checked out your rough water movie. Not surprised your Sonar went on the blink. They tend to like smooth water better. (some crew do too :mrgreen:

Cool, and tough boat. Probably more like recycled kegs, doubt it is just the "naked" cans :lol:

See you at Friday Harbor :?:

Harvey
SleepyC :moon
 
I took my Garmin transducer off of my transom after erratic readings and mounted it inside the cabin in the bilge under the stove (after discussing this with Garmin). This has solved all problems-the transducer is out of harm's way-only issue is slow response time to water tempeature.
Pete
 
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