Running a depth finder out the water??

[endless]

I called lowrance today about my Hook 2 7TS and she was going over my depth finder and stuff... told me to power it up and read her what it’s doing... I told her it’s not in the water and she said that’s fine doesn’t need to be and will give me reading either way????

 

but reading up on depth finder and running out of water from what I’m reading is a big no no and can burn the transducer up.....

 

can anyone help enlighten me?? 

[Russ E]

My bow depth finder is on the whole time my boat is in the water. It has a trolling motor mount transducer, so it is in and out of the water multiple times every trip.

I have done this for 30 years and not had one issue.

Banging the transducer on rocks and stumps is a different story. I have replaced a few because of that.

[Jig Man]

My console unit got accidentally left on for 3 days in the garage.  No harm done to the unit or ducer.

[Bankc]

I guess it could be an issue on some.  A fish finder transducer is just a speaker and a microphone.  I believe they're piezoelectric speakers and microphones, due to the need for efficiency at such high frequencies (although I could be wrong, I haven't looked it up).  If they're not overbuilt for the task, I could see how they might overheat, and need to be submerged in water to help assist with cooling.  Water has good thermal conductivity and exceptionally high specific heat capacity, making it an excellent choice for convective cooling. That's why they use it in everything from automobile engines to nuclear power plants.  That being said, you could also just overbuild the piezo speaker so that under normal operating circumstances, you're not pushing it anywhere close to it's limits.  In such a case, it would be fine to run it in open air, as it would never build up enough heat to require being submerged in water.  

 

So if the manufacturer says it's alright, then it's probably alright.  The transducer is probably overbuilt enough to not need the extra cooling effects of water.  If nothing else, that TS transducer is huge, so it might have enough surface area to effectively cool on it's own.  But other than cooling, I can't think of any logical reason why it would need to be in water.  I own several other piezoelectric speakers and microphones that operate fine in air, and will actually get destroyed if you submerge them in water.  

[schplurg]

I was told, perhaps here or perhaps Garmins site, that a 500 watt RMS or less transducer is okay to run out of the water. Anything higher may run too hot. Don't take my word for it though.

[king fisher]

Transducers can over heat if ran out of the water for a long period of time.  I don't think you could hurt a 500 watt transducer, which is what comes with most units made for fresh water.  I do know you can ruin a 2 or 3 KW transducer by running it out of water at max power output. I  Personally know of one that was left on for a few days while boat was hauled out for repairs.  Transducer cost $3000 to replace.  That captain will not make that mistake again.  I would not worry about a 500 Watt or even a 1 KW. transducer.