Need Help on a Transducer

[Thomv]

Recently my son gave me a Garmin Model 525 GPS. I was able to mount it above my dash. I now want to purchase a transducer to enable me to get depth readings off my unit. I was thinking of going with a transducer that would be mounted to the inside of my hull but I now have read that it the deadrise is higher than 15 degrees it will not work. My boat has a deadrise of 24 degrees so I guess that type of transducer will not work. My next option would be one that is mounted to the back of my transom which I would not like the look of something hanging off the back of my transom. Is there a way to be able to go with option one inside the hull?

 

[littlerayray]

Re: Need Help on a Transducer

i would pay the extra money and have it done by a marina and get them to drill through the transom thats what im doing and its gonna cost me about 150 dollars maybe less for you because you already mounted your gps and you wont see the wires and everything will be hidden

 

[tazrig]

Re: Need Help on a Transducer

You can also have have a "through hull transducer" installed. It is put in by having a hole drilled into the bottom of the boat near the stern. Then you wouldn't see the transducer or the wires. Either way is preferable and more reliable to having an "in hull" transducer.

 

[Thomv]

Re: Need Help on a Transducer

You can also have have a "through hull transducer" installed. It is put in by having a hole drilled into the bottom of the boat near the stern. Then you wouldn't see the transducer or the wires. Either way is preferable and more reliable to having an "in hull" transducer.

I would be really hestitant about drilling a hole in my hull. Looks like the hole diameter would be pretty large to fit the truough hull transducer. I still would have the problem on the deadrise being 24 degrees which is over what the manufacturer states a maximum of 15 degrees.

 

[Bondo]

Re: Need Help on a Transducer

I would be really hestitant about drilling a hole in my hull. Looks like the hole diameter would be pretty large to fit the truough hull transducer. I still would have the problem on the deadrise being 24 degrees which is over what the manufacturer states a maximum of 15 degrees.

Ayuh,.... It would be installed with a shim block to bring it nearer to a straight Down shot...

 

[dingbat]

Re: Need Help on a Transducer

A very common problem with an easy solution. You can install an Airmar B60-20 thru hull transducer or an Airmar P79 if you want a shoot thru installation.

You can also have have a "through hull transducer" installed. It is put in by having a hole drilled into the bottom of the boat near the stern. Then you wouldn't see the transducer or the wires. Either way is preferable and more reliable to having an "in hull" transducer.

There are thousands of Airmar P, M and R series transducer users that would disagree with your accessment of an in-hull installation.

 

[tazrig]

Re: Need Help on a Transducer

A very common problem with an easy solution. You can install an Airmar B60-20 thru hull transducer or an Airmar P79 if you want a shoot thru installation.

There are thousands of Airmar P, M and R series transducer users that would disagree with your accessment of an in-hull installation.

Airmar makes a good product for sure. I have one (p66 smart transducer running off the transom) hooked up to my MFD. I also have a "through the hull transducer hooked up to a dedicated meter for when I'm not using the MFD. But even Airmar claims that a through the hull transducer will give you:

"This installation, when mounted
in “clean water” forward of propellers and running gear, produces the
most effective signal return, since nothing on the vessel interferes with the
transducer’s active face..."

See page 5 of their product brochure:

http://www.airmartechnology.com/uploads/brochures/AIRMAR Transducer Guide 2009.pdf

 

[dingbat]

Re: Need Help on a Transducer

Airmar makes a good product for sure. I have one (p66 smart transducer running off the transom) hooked up to my MFD. I also have a "through the hull transducer hooked up to a dedicated meter for when I'm not using the MFD. But even Airmar claims that a through the hull transducer will give you:

"This installation, when mounted
in ?clean water? forward of propellers and running gear, produces the
most effective signal return, since nothing on the vessel interferes with the
transducer?s active face..."

See page 5 of their product brochure:

http://www.airmartechnology.com/uploads/brochures/AIRMAR Transducer Guide 2009.pdf

I don't rely on claims.

I've run P66, P79 and now a B164 on my personal boats and I spend a lot of time on a boat running a M260. My first hand experience and observations.

I had a P66 on a Sitex CV 106 MK2. The transducer performed OK but I couldn't get a clear picture over 20 kts. so I installed a P79. I lost 2 points of sensitivity with the P79 but I could run WOT with a clear picture. Which performed better?

Sold that boat and bought one that came with a Lowrance LCX15C with a P66. I hated that unit. Sold it, bought the Furuno 585 and installed a B164 thru hull. I've very happy with the B164 but it doesn't come to close to the performance of the M260 in-hull. It's noticable.

 

[tazrig]

Re: Need Help on a Transducer

I've run a transom mount and had pretty good results except during some high speed runs. (turbulence) I tried an in hull and it wasn't as fast to recycle (giving me new readings) I kept that one until it broke free of the epoxy base. Then after asking around and checking with a couple of different manufactures I switched to a through hull. That seems to be working out the best for me. No loss of signal and fast refresh rates. I have twin I/O's on the boat. The underwater disk is located about 2.5 feet up from the transom. If a through hull transducer works for you and stays put then you're golden. You're also lucky you didn't have to drill through the bottom of your boat. In my case the dealer, manufacturer and a bunch of people who had tried out the different transducer types on similar hulls were all in agreement. Through the hull was the way to go.

 

[dingbat]

Re: Need Help on a Transducer

I've run a transom mount and had pretty good results except during some high speed runs. (turbulence) I tried an in hull and it wasn't as fast to recycle (giving me new readings)

You had something else going on. A shoot thru does not slow down your refresh rates unless the installation was messed up.

You're also lucky you didn't have to drill through the bottom of your boat.

I have A B164 in my personal boat. Requires a 3 7/8" diameter hole thru the bottom of the boat.

 

[tazrig]

Re: Need Help on a Transducer

You had something else going on. A shoot thru does not slow down your refresh rates unless the installation was messed up.

I had it professionally done. The way it was described to me (by a tech guy at the manufacturer) was that sound doesn't travel as fast through fiberglass as it does through water so the refresh rates wouldn't be quite as fast. He said it took a hair longer to go through the glass when sending and again when listening for the signal to come back to interpret it. I also have a particularly thick bottom and he said that just added to it.

 

[Thomv]

Re: Need Help on a Transducer

A very common problem with an easy solution. You can install an Airmar B60-20 thru hull transducer or an Airmar P79 if you want a shoot thru installation.

There are thousands of Airmar P, M and R series transducer users that would disagree with your accessment of an in-hull installation.

I used the limk for the Airmar P79 and it states it will work up to a 22 degree dead rise. My dead rise is 24 degrees. Will that be a problem?

 

[tazrig]

Re: Need Help on a Transducer

I used the limk for the Airmar P79 and it states it will work up to a 22 degree dead rise. My dead rise is 24 degrees. Will that be a problem?

What that means is that you can adjust it to shoot straight down if your hull angle is up to 22 degrees. If your hull angle (dead rise) is 24 degrees that means you would be shooting at a 2 degree angle off of perfect dead center straight down. The deeper the water the more it would be reading off to one side of the boat or the other. For all practical purposes (at least at any depths that would get you into trouble) it won't make any real difference for you. In other words at 100 feet you might be reading what is a couple of feet to the left or right of what is directly under your boat. At 10-20 feet under you, you'd most likely be pretty much dead center. To put this into perspective. Even if it was perfectly set to straight underneath you, just the boat rocking slightly would point the transducer to the left or right of what was directly under the boat. Bottom line 2 degrees is nothing to worry about.

 

[Thomv]

Re: Need Help on a Transducer

What that means is that you can adjust it to shoot straight down if your hull angle is up to 22 degrees. If your hull angle (dead rise) is 24 degrees that means you would be shooting at a 2 degree angle off of perfect dead center straight down. The deeper the water the more it would be reading off to one side of the boat or the other. For all practical purposes (at least at any depths that would get you into trouble) it won't make any real difference for you. In other words at 100 feet you might be reading what is a couple of feet to the left or right of what is directly under your boat. At 10-20 feet under you, you'd most likely be pretty much dead center. To put this into perspective. Even if it was perfectly set to straight underneath you, just the boat rocking slightly would point the transducer to the left or right of what was directly under the boat. Bottom line 2 degrees is nothing to worry about.

That is reassuring. Thanks

 

[dingbat]

Re: Need Help on a Transducer

double post

 

[dingbat]

Re: Need Help on a Transducer

I had it professionally done. The way it was described to me (by a tech guy at the manufacturer) was that sound doesn't travel as fast through fiberglass as it does through water so the refresh rates wouldn't be quite as fast. He said it took a hair longer to go through the glass when sending and again when listening for the signal to come back to interpret it. I also have a particularly thick bottom and he said that just added to it.

Sound travels faster thru fiberglass almost twice as fast (2740 m/sec) than water (1480m/sec). Even if your fiberglass was a foot thick, it would take the signal an additional (0.3 /2740 m/s) = 0.000019 seconds which is unperceivable

The only thing that could account for the phenomenon is an air space between the water and the transducer.

Your sounder averages a set of data points to determine the depth. The number of data points is determined by the update rate. The faster the update rate, the fewer data points, the less certainty of the result.

The unit is also checking for errors in the data. If a value is outside of a percentage of the expected value, the data is ignored.

Example: The unit is set to average 10 returns between updates. The first 10 returns are 10,9.8,9.8,10,10,9.8,9.8,10,10,9.8. It averages the figures and updates the display to 9.9 feet.

It then looks at the next set of returns. This time your getting some turbulence and some of the data point are outside the expected norm so the data is ignored. It will not update the display until it gets a set of data it can reconcile. If the process takes too long, the depth goes blank or flashes to let you known the unit cannot reconcile the depth with the data supplied.

 

[Thomv]

Re: Need Help on a Transducer

I just found out, through Garmin, that my Model 525 will not accept any type of transducer because it is missing the electronics to support the transducer. I was under the impression that the only difference between the model 525 and model 525s was that the 525s came with the transducer and everything else was the same but that is not the case. So, moving forward, what is a good reliable 2 1/2 inch diameter depth meter at a decent price?

 

[tazrig]

Re: Need Help on a Transducer

So, moving forward, what is a good reliable 2 1/2 inch diameter depth meter at a decent price?

Just this past Thursday I finished with my re-power and sea trialed my 1976 Formula 23' Formula with a new Faria 2 1/2 inch diameter depth finder model # FAR 13894.


http://www.faria-instruments.com/docs/fm-001-0030_D_Faria-Depth_Sounders.pdf

Faria Digital Depth Sounder - iboats


I got mine with the "through the hull" transducer but you can also get it with a transom mount or an in hull transducer if you prefer. Anyway it gave rock solid readings all the way up to 60mph. which was wide open throttle. It never lost tracking even in steep turns. I wouldn't hesitate to highly recommend this unit. I did a bunch of research before getting it as I believe if you put in real quality stuff it will give you the least amount of trouble down the road. There are also cheaper units out there. Just though I'd let you know about my test results from a couple of days ago.

 

[Thomv]

Re: Need Help on a Transducer

Just this past Thursday I finished with my re-power and sea trialed my 1976 Formula 23' Formula with a new Faria 2 1/2 inch diameter depth finder model # FAR 13894.


http://www.faria-instruments.com/docs/fm-001-0030_D_Faria-Depth_Sounders.pdf

Faria Digital Depth Sounder - iboats


I got mine with the "through the hull" transducer but you can also get it with a transom mount or an in hull transducer if you prefer. Anyway it gave rock solid readings all the way up to 60mph. which was wide open throttle. It never lost tracking even in steep turns. I wouldn't hesitate to highly recommend this unit. I did a bunch of research before getting it as I believe if you put in real quality stuff it will give you the least amount of trouble down the road. There are also cheaper units out there. Just though I'd let you know about my test results from a couple of days ago.

I think I will also go with the Faria unit. I agree with you regarding quality. Thanks for the link.

 

[weekender1]

Re: Need Help on a Transducer

i have a question about a depth sounder my boat came with one that is a transom mount and then is ran to a 4" round dial that spins when i turn it on even in water the dial just spins fast so i dont know if mine is shot or not i will get a pic as soon as i can. also if you want to move this i can understand or if i should start a new thread?