Through hull transducer location

[Denis]

I am going to be buying a new RADAR/Chartplotter/fishfinder for this summer. I'm a little nervous about this next part, but I will need to drill a hole through the bottom to add the transducer. I'm sure there are plenty of you that like to fish out there, could you please let me know the location of your transducer and are you happy with it's operation. What type of transducer would you recommend? I am also pretty sure I will need to remove the core and add solid glass around the hole in the hull. Thanks for your suggestions. D.

[Russell]

I had a new fishfinder installed 2 years ago and had an Airmar tilted element unit put in the same hole that the old one came out of. I like it because nothing projects from the hull. Someone mentioned a while ago that close to the keel is a section of solid fiberglass that would allow the use of a shoot-thru-hull transducer and if you do not already have a hole in your hull, I would consider that. You can put it in a bag of water and move it around to find the best transmission before mounting it in place.

[Pitou]

The Albin hulls were built with specific areas that are all glass and no core in order to accept thru-hulls and transducers. I know this to be the case with my vintage. Check with the new Albin Company or a local dealer (current or former) to help you determine exact locations. I have an Airmar mounted in a fairing block port side to the rear of the deck hatch next to the engine box as well as a puck sounder for my digital Raytheon in the same location to starboard. The Airmar hold s a read pretty well unless the seas get 2 1/2 plus and I'm pushhing over 16 ish knots or so. The puck loses its ability over 1 - 1 1/2 under the same conditions. Otherwise both read just fine.

Research those solid glass areas and you may not have to clear out and seal the cores. I do suppose this may not be the case on all of our boats as I am sure this may have been something that evolved and was added over the years. Nothing like a dealer who was around for a while to help you out.

[mackidaddy]

Only thing I can add is not to cut a hole too close to the engine block. My Albin dealer cut a hole for the ducer pretty close to the engine. Once the engine warms up, it exxagerates water temp. Not sure if they cut through a solid glass section or core. Not interested in finding out an answer that will only fire me up more. Please learn from my dealer's oversight. Find a location AWAY from the engine.

[furball]

Denis,
My transducers performs about the same as Pitou, I lose it at higher speeds in the chop.
Here's a photo of the location.

I think if you can move closer to the centerline, you'll keep bottom better at 16-18knots.
Good Luck
John

[Denis]

Thanks for the information and suggestions. I am going to talk to a mechanic who might know about the hull construction of a boat my vintage. I can probably look on line but how does the transducer not project down below the hull? Come to think about it, I have a depth sounder only right now with a transducer. I can probably take that one out and use the hole. I don't know if it's because of the location of the transducer or the depth finder quality itself, but I lose the bottom often and at many speeds, maybe that is not a good place for the transducer to go. I would think the closer to the centerline of the boat the cleaner the water would be?

[Russell]

Denis Here is picture of the Airmar angled transducer. It is nearly flat to the hull and looks like a little porthole on the bottom of the boat. It includes temperature but not speed through the water. Speed over the bottom is more important for fishing, so I did not care about the water speed. My transducer is mounted a little over a foot aft of the bulkhead between the forward and engine compartment and a foot port of the centerline. If there is a chop the picture has gaps but if we slow to 2000 rpm we can get a nice view of the bottom.

[Denis]

That is a great shot of the transducer. I see that it is drilled at 90 degrees to the hull and that the internal components are adjusted for the angle of the hull. Do you adjust that angle or buy a transducer that has the angle built in? Sorry for all the questions but I hate the thought of making a mistake at this point.

[Russell]

The tilted element transducers come in 12 and 20 degree angles. I believe mine is the 12 degree but you can measure the angle of the hull on the inside and pick the one closest. My system is the Furuno Navnet but I think all the companies use Airmar transducers and you just select it from their catalog. You can also go to the Airmar marine website and click on your manufacturer and thy show you the transducers available. By the way, my old transducer in the same hole had a faring but it did not work as well as the new one. I think the smooth hull surface creates less turbulence at speed and also gives a little less resistance through the water.

[RobS]

Installed a new Furuno FCV620 fishfinder and thru-hull transducer with high speed fairing block. Works extremely well - keeps a solid depth reading including very low water and at all speeds. Was checking WOT and was reading 3ft of water at over 22knots Solid readings at 1.75ft, 1.80ft, etc when i'm idling back in.

Very happy with the ducer and the the fishfinder. Here's some pics to show the ducer and it's location. This is an engine box model and it's mounted just fwd of the plywood bulkhead btwn the engine compartment and the battery area and down deep towards the centerline.

[Pitou]

Rob,
Thanks for the pics. It appears your transducer is further into the bilge on the other side of the stringer than my set-up. Looking forward to seeing yours at the NE Rendezvous .... next year is electronics replacement time and I need a better FF/Sounder and want to do everything I can to keep it reading accutately.

[Russell]

Rob: Why did you decide against the tilted element transducer?

[RobS]

Kev:
Here's a shot of the FCV620 I went with. I used the RAM mount which allowed me to get the unit high and tight to the pilot house roof.

Russ:
My local waters are infamous for being quite thin on water. A main reason for the ducer upgrade was to get a solid reading at all speeds, especially cruise and I felt more comfortable with the high-speed fairing block since I had personal experience on prior boats. I also wanted to be 110% sure that the element was pointing straight down as I am over wrecks (some up to 200ft deep) regularly fishing and diving. Last year was my first full season with this boat and I always had trouble positioning her over the wreck. When I was on the numbers the marks were not there, and visa versa. Turns out the old fairing block was not cut perfect and she was tilted slighty outward. Another reason for going with the triducer was that I did not want to give up the STW feature of the fishfinder, although SOG is more important, if a feature is there, why give it up. Nothing against the tilted element and the tilted element was recommended to me both by Airmar and Furuno.

[Pitou]

Rob - thanks for the pictures. I went forward and gave the local shop, Voyager Marine, the go ahead with the FCV 620 yesterday at 3 PM. I will copy your overhead mounting with the RAM, but have decided against the fairing block transducer and have gone with the new puck in the same location as the old transducer, port of the port stringer in the rear of the cockpit hatch next to the engine box. We'll see how she performs.

I called this morning and the old transducer and fairing block is out and the glass guy is already there this morning. The job will be done by weeks end!

I had a friend say to me last night "good luck this time of year, you'll be in maybe mid June." This shop has always given me quick response in the past as I have heard many whine that they have to wait. It probably has something to do with my fine manners, ability to suck up and quick turnaround when the bill arrives! Truly, kudos to Jon at Voyager Marine. It's nice to be within a 1/2 mile of their shop as what so often happens is when a tech finishes early when on the road they stop at the local marinas to round out their day.

I checked out the new NAVnet 3D ..... sweeeet! The ole' Simrad will be headed south next season for sure!

[RobS]

....I will copy your overhead mounting with the RAM...

You will be pleasantly surprised with the quality of this item. This company makes all kinds of mounts, like laptop's in police cruisers, etc. The mount is simple and robust and does what it's supposed to do. Glad to help. Here's a couple more pics.

John,
I did not mean to hijack this thread. I do not have moderator control of this forum - should we break it up?