Question on mounting transducer

[DollarBoat]

I recently picked up a new Raymarine Axiom system and had a question on mounting the transducer. I know you’re supposed to just have the bottom of the transducer below the hull by about an 1/8 to 1/4 inch to get clean water but since my transom is angled quite a bit, when looking the back of the boat, the right side of the transducer will be lower in the water than left side.

So my question is, should the left side of the transducer sit slightly below the hull or the right side of the transducer?

 

[walleyes]

Put it so the left side is slightly below the hull. You want the transducer to be completely in the water when under way not partly out. You may get a little more spray this way but that’s just the way it will have to be.
This is the way I would do it anyways.

 

[gungadin]

Sounds like your boat has a lot of deadrise at the stern. Unfortunately mounting the transducer so that it is parallel to the deadrise will not allow the transducer to show you what is under your boat. You absolutely need to mount the transducer so that it points directly down into the water beneath your boat. In your case this will mean one side will be deeper in the water and will result in a rooster tail when travelling at speed. There are shields available to reduce or eliminate this rooster tail.

 

[DollarBoat]

Ok thanks. It makes sense that the whole transducer needs to be in the water and therefore in my case the right side of mine might be lower than ideal so that the left side is slightly below the hull. I’ll give it a try and see what happens.

 

[MikePA]

Sounds like your boat has a lot of deadrise at the stern. Unfortunately mounting the transducer so that it is parallel to the deadrise will not allow the transducer to show you what is under your boat. You absolutely need to mount the transducer so that it points directly down into the water beneath your boat. In your case this will mean one side will be deeper in the water and will result in a rooster tail when travelling at speed. There are shields available to reduce or eliminate this rooster tail.

Can you recommend where to get a shield.. the back of my boat gets pretty wet when under way. I have a Lowrance hook 7. Thanks.

 

[Rockfish]

As I understand it, that especially on shallow draft boats, that sometimes the open style transom mounting brackets for the transducer will redirect water up in a spray fountain and that this is cured by blocking/shielding it so that the open spaces in the bracket don't catch and redirect water spray upward.

 

[Bearded wonder]

Can you recommend where to get a shield.. the back of my boat gets pretty wet when under way. I have a Lowrance hook 7. Thanks.

On my old boat I had the same problem. I just wrapped some 1” wide electrical tape around the mounting bracket a few times covering the open space in the middle. . It was quick and very cheap. Figured it was a temp fix till I found a better solution but it held up for the season.

 

[MikePA]

On my old boat I had the same problem. I just wrapped some 1” wide electrical tape around the mounting bracket a few times covering the open space in the middle. . It was quick and very cheap. Figured it was a temp fix till I found a better solution but it held up for the season.

Ok, thanks, I'll give this a try!

 

[Bearded wonder]

Ok, thanks, I'll give this a try!

You got nothing to lose.

 

[gungadin]

Garmin makes one for their transducers, but most I have seen are homemade. Made from aluminium, stainless, or plastic. I made one out of a toilet bowel flange and drainpipe. Looks awful but works.

 

[DollarBoat]

So I tried the boat today with the new system installed. When I get above 10 MPH it loses the bottom snd there definitely is a good size rooster tail coming from the transducer. Does that mean it’s mounted too low?

 

[walleyes]

So I tried the boat today with the new system installed. When I get above 10 MPH it loses the bottom snd there definitely is a good size rooster tail coming from the transducer. Does that mean it’s mounted too low?

Something is wrong, with today’s units you should be able to track bottom to 30 - 40 mph in 300’ easily. My 06’ Lund equipped with what is older Garmins now would track bottom in 300 + feet at 40 mph.
If you could get us a couple pics maybe we could pick out what the issue is. I’ve mounted a few of them over the years and have never had an issue.

 

[DollarBoat]

Ok thanks. The boat is in the water now but I’ll pull it in a few days and take a picture of the position.

 

[N2013]

I have an 185 DE with lowrance hook 7. Tried various positions for the transducer and couldn't get rid of the spray. I ended up just mounting it higher, just out of the water when on plane, thus eliminating the spray. I still hold bottom when I'm positioning to try to get on top of a pinnacle or else looking for bait. I just look at my plotter to find out where I am in relation to the bottom when I'm running.

 

[Oly1]

Slight derail, but was wondering how other members are mounting their transducers on a smaller 14 foot tinny. Would rather not drill holes through the aluminum transom.

Oly

 

[tinboatrobb]

I drilled and sealed hole in the transom of my 14 ft lund. Been 6 years and no leaks.