Sputter, sputter, choke, choke...
Your chart was correct for, oh, say, 2003, but NOT 2014.
That's why they have LNMs as well as online charts for you to be able to correct.
It was NOT the chart's fault.
depth finder puck
- Thread starter trainmanjess
- Start date
Your chart was correct for, oh, say, 2003, but NOT 2014.
That's why they have LNMs as well as online charts for you to be able to correct.
It was NOT the chart's fault.
Generally you would be well advised to follow the directions in the manual, you know, RTFM.
In this case it is important to understand that Humminbird markets primarily to power boats and not to sailboats. Sailboats and powerboats have very different hull characteristics and so the placement of the transducer is dependent on the type of hull. The issues become clear when you understand how depth sounders work.
Depth Sounders and fish finders are sonar devices, they send out a very high frequency ping and wait for the pings echo. The faster the return the shallower the water. Any thing that impedes the transmission of the ping will degrade the depth sounders performance.
What impedes the transmission?
Top of the list is a cored hull. Both foam and balsa core will effectively block transmission.
Lots of growth on the bottom of the hull, sound doesn't transmit very well through the slime and crap that grows on the bottom of the boat.
Soft or weedy bottoms on the lake or sea floor. The pings don't echo.
Air bubbles in the hull lay up or the adhesion method.
Turbulent water. This factor is important when considering placement. In powerboats, the puck needs to be in the stern because the water there is not as turbulent as it is in the bow and when on plane, the bow of the boat is not even in contact with the water. Sailboats need the puck in front of the keel, because the water behind the keel is disturbed and turbulent which impairs transmission. The puck also needs to be parallel to the waters surface and close to centerline on a sailboat, think of the boat heeling and what the puck is looking at.
Before you glue the puck down, use the puck in a bag of water method to make sure the puck will work where you intend to place. Put the puck in a bag, fill it with water and seal the top, plug it into the display and power it up. If you can't get a reading with a little fiddling, then find another spot.
I've used silicone to set a puck and it worked well for many years. However, the manual said I could use a high quality marine silicone sealant and I did. If Humminbird recommended epoxy, then use epoxy, get a small repair kit from West System and mix up a small batch.
Whatever method you use, make sure the contact between the puck and the hull is solid and free of any voids. Many boats have a rough interior side to the hull because from the roving used in the construction, make sure the valleys and dips are filled with the adhesive. Regardless of the adhesive you use cleaning up the area with some acetone and sandpaper will help the puck adhere.
So do what the manufacturer says, except in Humminbird's case if they recommend placement the back of the boat, that's fine for a power boat, not so good with a sailboat.
One other thought. In very weedy areas, depth sounders will sometimes read the top of the weeds as the bottom and not the bottom. Charts and local knowledge will help you know if the problem is shallow water or weeds. Often you look over the side and see the weeds, that's a big clue.
"So do what the manufacturer says, except in Humminbird's case if they recommend placement the back of the boat, that's fine for a power boat, not so good with a sailboat."
That was my exact conclusion based on what they describe. It's in the text, not the pics. - Thanks
That was my exact conclusion based on what they describe. It's in the text, not the pics. - Thanks
TS,
I forgot to reply to your earlier post about markers, numbering & locations vs. charts.
If I will be sailing in areas I am NOT familiar with, I use the Local Notice to Mariners.
It's here you may find if markers or bottoms change.
http://www.navcen.uscg.gov/?pageName=lnmMain
Paper charts are never up to date & things change.
CR
I forgot to reply to your earlier post about markers, numbering & locations vs. charts.
If I will be sailing in areas I am NOT familiar with, I use the Local Notice to Mariners.
It's here you may find if markers or bottoms change.
http://www.navcen.uscg.gov/?pageName=lnmMain
Paper charts are never up to date & things change.
CR
Jess,
In the future may I suggest that part of your original question should be to include as many facts as you can.
You failed to mention your boat was full keel. I believe most assumed a fin keel hence, theirs & my posts. Without all the details up front, the answers will suffer. In addition to facts, sometimes pics will clarify alot.
I'm not trying to beat you up, just to help you pal.
CR
Back to the original problem
The max material that that transducer can see through is probably 3/8 of an inch.
How thick is your hull?
In order for mine to work I had to cut into the hull and make a pocket to put the puck into. In order to know the depth of the remaining hull, I drilled a 3/16 hole all the way through the hull. I hogged out a pocket until I measured 3/8 though the hull in the drilled hole. Once done I used a countersink to make the bottom of the hole on the outside of the hull a v shape. I then used the THICK marine epoxy from True Value that is like putty when used. No air bubbles! I filled the bottom of the pocket pushing into the hole though the hull. Once I had the pocket filled I went under the hull and put epoxy into the counter sink and put a piece of tape over it. All done.
The max material that that transducer can see through is probably 3/8 of an inch.
How thick is your hull?
In order for mine to work I had to cut into the hull and make a pocket to put the puck into. In order to know the depth of the remaining hull, I drilled a 3/16 hole all the way through the hull. I hogged out a pocket until I measured 3/8 though the hull in the drilled hole. Once done I used a countersink to make the bottom of the hole on the outside of the hull a v shape. I then used the THICK marine epoxy from True Value that is like putty when used. No air bubbles! I filled the bottom of the pocket pushing into the hole though the hull. Once I had the pocket filled I went under the hull and put epoxy into the counter sink and put a piece of tape over it. All done.
Clearly something 1' below the puck is causing a problem. These suckers work off reflected ultrasonic sound waves. Those are reflected by changes in density. If you have a full keel is it a wood boat?, is the keel made of a different material than the hull. Two layers of slightly different wood or wood/fiberglass will reflect most of the sound and give you a problem. What is about 1' below the puck? I've also seen that offsetting from the keel center line can also cause the sound waves to be reflected 90 degrees off the hull hit the hull on the other side and be reflected back to the puck so think 4-6" below the puck is the problem if you are not on the CL
LOL-This was 2010, vs 2011, on a return leg from the Bahamas. And no, it definitelly was NOT the charts fault. Twas mine.Sputter, sputter, choke, choke...
Your chart was correct for, oh, say, 2003, but NOT 2014.
That's why they have LNMs as well as online charts for you to be able to correct.
It was NOT the chart's fault.
installation
Yes the Mfrs like their products to be installed the way their engineers specify.
And, if you want the best imaging of twigs and fishies under your bass boat, then transom mounted in the water or bedded in a clear plastic resin against solid fiberglass will do that.
I have a Lowrance transducer caulked to the solid glass hull just aft of the keel and on a slope of at least 15, maybe 20 degrees. I get a steady and accurate depth Number on the display. Imaging is not what I'm after.
Is the Hull Cored? Is there a scaly mass of bottom paint involved? In a full keel boat, the turn of the bilge may not give a low enough angle for a good echo either. How far away from the centerline must it be to avoid an echo from the keel? I would try testing forward for that reason. Some dual band transducers have different widths of the beam focus. Can that be selected? Very few of these gizmos were designed with sailboats in mind. Especially the fish finder types. We are a bunch of deviates with our non-standard installations. I bet customer service reps have eye-rolling episodes when we call in, and cartoons on their cubicles of 'those crazy sailors'.
Yes the Mfrs like their products to be installed the way their engineers specify.
And, if you want the best imaging of twigs and fishies under your bass boat, then transom mounted in the water or bedded in a clear plastic resin against solid fiberglass will do that.
I have a Lowrance transducer caulked to the solid glass hull just aft of the keel and on a slope of at least 15, maybe 20 degrees. I get a steady and accurate depth Number on the display. Imaging is not what I'm after.
Is the Hull Cored? Is there a scaly mass of bottom paint involved? In a full keel boat, the turn of the bilge may not give a low enough angle for a good echo either. How far away from the centerline must it be to avoid an echo from the keel? I would try testing forward for that reason. Some dual band transducers have different widths of the beam focus. Can that be selected? Very few of these gizmos were designed with sailboats in mind. Especially the fish finder types. We are a bunch of deviates with our non-standard installations. I bet customer service reps have eye-rolling episodes when we call in, and cartoons on their cubicles of 'those crazy sailors'.
I have used both silicone and plumber's putty to bed transducers inside the hull. Both work most of the time, but there is the occasional hickup. I haven't determined if it is because of the bedding material used or air/turbulence on the outside of the hull that disrupts the signal (they are both about 18" off the center line, midship on a fin keel Gulf 29). A boat builder recommended that I should use epoxy. When I mentioned the desirability of possibility removing them or relocating them, he suggested putting a coating of wax on the transducer before bedding it in epoxy.
Robert,
How then will the wax work for insuring the puck stays in place say, If on a high/low frequency vibrating sail/powerboat?
I personally, would check the Garmin site where I got my puck. It came with a caulk & worked fine. See if you can get the caulk specs. Look for something similar, as it is for transmitting transducer pings. I have also used latex caulk on some, epoxy on others. I've never experienced a failure.
Take zip-lock bag, 1/3 water filled. Insert puck & hold to hull. With unit on, move puck around until you get a solid steady read. Mark spot, attach puck.
Some like epoxy, I don't incase I need to change it out. I would want to re-use the same spot.
That's it, this is not rocket science.
CR
How then will the wax work for insuring the puck stays in place say, If on a high/low frequency vibrating sail/powerboat?
I personally, would check the Garmin site where I got my puck. It came with a caulk & worked fine. See if you can get the caulk specs. Look for something similar, as it is for transmitting transducer pings. I have also used latex caulk on some, epoxy on others. I've never experienced a failure.
Take zip-lock bag, 1/3 water filled. Insert puck & hold to hull. With unit on, move puck around until you get a solid steady read. Mark spot, attach puck.
Some like epoxy, I don't incase I need to change it out. I would want to re-use the same spot.
That's it, this is not rocket science.
CR
