[wopalx]

We have an Airmar DST800 triducer fitted to our XP38 supplied by Raymarine and installed by a professional marine electronics company of good standing.

The original installation was done when the boat was launched in 2012.

We had a failure of the automatic flap (which prevents water ingress when removing the transducer) after about 2 months and the installer hauled out the boat and replaced the faulty unit at their cost.

During 2013 we again had the flap fail.

In March 2014 we replaced the transducer and through hull with another DST800 during our annual haul out at our own cost, again it was installed by the same company.

After the second use the flap again failed...

From discussions I've had with the installer they don't believe they have done anything wrong, so hence I need to have the discussion with Raymarine. While I'm sure they will come to the party and replace the faulty unit I doubt they will cover any haul out or installation costs which obviously sucks big time!


So I am interested in finding out if other people have had issues with the Airmar DST800 tri-ducer, specifically in regards to the flap failing.

Also what are peoples opinion regarding installation / haul out costs? Should I push Raymarine into covering these..

Information I have from Raymarine is that Airmar made adjustments to the design in 2010 as they had issues with flap failures, I suspect they may not have sorted the issue.

 

[SVAuspicious]

The thru-hull has to be installed in the correct orientation for the flap to work reliably.

What is the nature of your failure? The flap can't be expected to completely stop water flow, only to slow it down considerably.

 

[wopalx]

Nature of the failure is the flap falls out of the transducer tube and disappears. Hence we get a massive gush of water each time we change over the transducer for the blanking plug which is generally weekly in summer.

The water is easy enough to clean up however we would prefer to keep as much water out of the boat as possible for obvious reasons, hence wanting a flap that works more than once or twice

The company that has done the installation for us is one of the largest Raymarine installers in the area, and we have used them for fitting out of our past 3 yachts we have owned over the years. So I don't think they are installing it incorrectly.

Furthermore they are aware of all the tricks to look for during the installation from the following information from Airmar;

"The risk of the original valve becoming dislodged requires the ring to be positioned with the gap positioned directly over the valve hinge. Assembly instructions include the orientation of the snap ring with ring gap 180 deg from the valve hinge. An incorrectly positioned ring could occur during assembly, or during post-delivery handling. The ring can be rotated by hand from the "as assembled" orientation (180 deg from the valve hinge) during installation or subsequent handling. Please note, that with the snap ring gap located over the valve hinge (incorrect placement or subsequent manual rotation), the valve body remains securely retained within the housing, but includes a higher risk of failure due to the size of the snap ring gap and valve hinge. "


As indicated in my original post I'm curious to see if others have had similar issues with this transducer.

 

[WoobaGooba]

Weekly swap of the blanking plug and transducer? Do tell.

I've the same unit, though blank is only in place for the winter haul.

 

[wopalx]

We normally remove the transducer after sailing if we are not using the boat for more than a few days.

Stops it from getting gummed up with growth on the speed sensor / paddle wheel.

 

[Classic30]

I've had a few challenges with mine, but I simply can't be bothered swapping it out any more and often leave the blank in even when out sailing. It's one less thing to worry about where GPS speed is good enough.

To your question: IIRC there isn't just one flap, but two interconnecting flaps on opposite sides of the unit that close against each other - and I suspect mine is missing one, but I don't get all that much water in - certainly not full flow...

There are known issues around the size and lubrication of the O-rings on the body of the plugs, and if you try to force the plug in (or force it out more likely!) with an incorrectly sized or un-lubricated o-ring, you risk dislodging one (or more) flaps and losing them out the bottom of the boat. For this reason I'd find it really hard to believe they'd replace the unit no questions asked... but it'd be a bonus indeed if they were.

 

[SVAuspicious]

Nature of the failure is the flap falls out of the transducer tube and disappears. Hence we get a massive gush of water each time we change over the transducer for the blanking plug which is generally weekly in summer.

That's a failure. *grin* Haven't seen that one so I'll bow out.

Definitely a problem. Golly.

 

[Classic30]

Definitely a problem. Golly.

Nah.. not really.

Even with only one flap, you get a darned sight less wet than doing the same thing 20 years ago. Anyways it's a good excuse to (a) wash the bilges out and (b) test the bilge pump.

 

[wopalx]

Well if you pay for a product, several times, that is faulty it's a problem IMHO.

Issue with the water ingress is the transducer is located forward of an electrical distribution panel and all the electronic networks backbone. Salt water and electronics don't mix too well over the long term.

Also the water splashes all over the bow thruster, causing the s/s parts to corrode (s/s I don't think is as good as it used to be).

Have no issues with cleaning the bilge but fail to see why I should need to if the product worked as it's supposed to.

Nah.. not really.

Even with only one flap, you get a darned sight less wet than doing the same thing 20 years ago. Anyways it's a good excuse to (a) wash the bilges out and (b) test the bilge pump.

 

[Classic30]

So.. you hold the manufacturer responsible for the transducer being located in close proximity to gear that can get damaged by salt water? Why do you have all that stuff located in the bilge anyway??

 

[wopalx]

So.. you hold the manufacturer responsible for the transducer being located in close proximity to gear that can get damaged by salt water? Why do you have all that stuff located in the bilge anyway??

The thru hull is not in the bilge, it's forward in the forepeak area.

I don't hold the manufacturer responsible for damage to other items, simply I want the item to work as advertised / designed

 

[Whispering Wind]

I have a new Airmar triducer installation, with a single flapper in the thru-hull. I am experiencing a 17" v-shaped geyser when the ducer is removed, and you can see visually that the flapper valve is completely closed. We hauled the boat (again, more $$$) to confirm that the flapper was not defective. This is no BS - I couldn't get anyone to believe me so I made a video. If you haven't experienced this you need to see it. The geyser drenches the bilge and splashes the sole. You need three hands to remove the ducer, control the geyser, and install the plug.

For those with detached flappers, how would you describe the geyser you are experiencing?

How about anyone with flappers intact? What are you observing?

The speed ducer Airmar supplied with my OEM Raymarine instruments 13 years ago only "gurgled", producing about 4 oz of sea water during a rapid transition. This one must put out 2-3 times that. Sure, my geyser is better than no flapper at all but come on Airmar, what were you thinking? Does the benefit of combining speed, depth, and temperature in one ducer justify such a massive cleanup?

 

[wopalx]

Whispering Wind I responded to your post on SA.

In both cases the flapper has dissapeared. When the flapper was still in place we would get barely a drop of water coming in but we have always been pretty fast with swapping them over.

Likewise we had the older style Airmar transducers in our last boat and never once had an issue.

I've considered going to the older style and replacing the tri-ducer with separate depth and speed. However it would require a iTC5 box to interface and involve installing another hole into the hull which I'd prefer to avoid.

 

[Whispering Wind]

Thanks wopalx got that reply. I realize that the flapper design may have changed in the 2 years since your installation, but going from a drop of water to a geyser sounds highly unusual. I sent my video to Airmar and the initial response was that what I am experiencing is normal!?! After your flap detached, did you get a geyser? How high?

You mentioned going back to the older ducers combined with the Raymarine iTC-5 Instrument Transducer Converter as a possible fix. Does this convert the ducer output to N2K? I have B&G instruments so SeaTalk wouldn't work for me.

 

[wopalx]

You mentioned going back to the older ducers combined with the Raymarine iTC-5 Instrument Transducer Converter as a possible fix. Does this convert the ducer output to N2K? I have B&G instruments so SeaTalk wouldn't work for me.

Yes it converts the transducer output into what the ray marine displays need.

I've sent you a pm with my email address as I'd be interested in seeing your video.

 

[WoobaGooba]

Please post the video, thanks.

The model number being discussed is the DST800 series, correct?

 

[Whispering Wind]

Yes, this is the Airmar DST800 triducer spec'd by several instrument mfrs. Apparently there is no way to post video on this forum, so I have made it available on SA.

It shows very graphically how much sea water volume enters my boat with the flapper valve intact. You can see the flapper valve, along with its spring, in the closed position. The water bypasses the valve on 2 opposite sides, creating 2 symmetric geysers in the shape of a V. You can see the sole, located 16 inches above the thru-hull, getting splashed.

I would be very appreciative if anyone who has the DST800 triducer with flapper valve would weigh in on a informal poll:

For anyone who has suffered through a detached valve - how high was the geyser?

For those with intact valves - did you experience a gush of water into the boat anything like mine? Or just the minor gurgle that most people report with the smaller diameter speed transducers?

 

[WoobaGooba]

Just saw the video, thanks.

I'll pull my DST800 sender this weekend and check out the flow for comparison.

That said ... it is not my expectation that the DST800 flap will stop the water flow, just slow it down. And I'm coming from a former Datamarine fitting that had no flow inhibitor

Cheers

 

[Whispering Wind]

Thanks for weighing in WG. FYI, I pulled my ducer with the boat stationery. I expect that to be worst case scenario since flow should reduce as hull speed increases. If you have a chance to share some video or pics of pulling yours that would be great.

In light of the well documented potential for this unit to lose its flapper, I think it would be good to understand what to expect from a "normal" unit.

 

[MarkSF]

I've been using the DST800 for 3 years, and swap it for the blanking plug every time I sail. The jet of water you describe is normal, and the unit is working as designed. I've had no problems with the flap over about 300 swaps now.

What is at fault is your expectation. The flap is designed to reduce the volume of water during changeover, not to stop it.

My previous one had no flap - you should have seen the volume of water from that.

Think about the geometry for a minute - for the flap to fit flush inside the wall of the tube, it can't be a perfect fit inside it.