Transducer temps??

[RonSki]

It seems as if everyone is either staying home or not talking lately so I figured I'd try to stir the pot a little.

I've been hearing some crazy differences in water temps from what I get on my boat lately. I'm wondering if my transducer is telling me the wrong temp but when I'm actually at the same lake with someone else, our temps are similar. I'm not talking about a small difference either. I was told some people are getting temps in the 70's already but I haven't seen anything over 62. I know that temps will vary with the depth of the transducer, but as you all know, my boat drafts shallower than anyone elses so I SHOULD be getting the warmest temps, which isn't the case.

This really doesn't affect fishing that much, but when someone tells me it's 74 on one lake, and I go there the next day under similar weather conditions and get 60, something is going on. Too bad there wasn't a way to calibrate the temp.

I'm just wondering what everyone (if anyone is actually alive out there) is getting for water temps. I'd like to try to get some posts with the date, lake, and depthfinder model, (and also if it's on the trolling motor or not) just for comparison purposes. SOMEBODIES temp is wrong, just wondering who's.

The fish are NOT biting, so I have nothing left to do but to ponder tough questions such as this....;)

[Pat]

I haven't been muskie fishing for 2 weeks (at Loon). But bass fishing all over NE Indiana, I haven't seen water temps in the 60's for at least a week. I have a Humminbird 597ci (transducer-transom) on my Lund...so it sits a little deeper than some boats.

Big Turkey, Little Turkey, Palestine, Robinson, Sylvan, Crooked,-water temps mid/upper 70's.

Loon and Diamond were lower 70's.

[J Routt]

I had temps from 67-70 on the pay pond this weekend. Both of my transducers are on the back and read the same temps. Both Humminbird. Mine sits a little deeper than some, but I haven't been over 70 yet on Webster, Tippy, or Barbee. Been right at 70, but no more.

[TAN]

I had 71-73 last week at Bruce Lake, and 70-72 yesterday at Palestine.

I have two transducers - an Eagle on the trolling motor, and a Humminbird on the transom. They are usually about 1 degree apart, with the trolling motor usually reading higher.

TAN

[MACK]

I was at Webster this past weekend (against my will mind you...but that's another story). Anyway...fished from my old boat, which is now my brother-in-laws boat, the Pike Attacker. He has two fish/depth finders on his boat. Both are Eagle products. I don't recall the models exactly. One is about three or four years old...b/w model which is at the base of his bow-mounted trolling motor..the other...two season old now...lower-end Eagle model which is color and mounted off the transom. :shrug:

He and I fished for muskies for about 4 hours on Saturday morning. Early am both of his electronics showed surface temps at 68 and by the time we left the water at 9:30 am....we had found some areas at 70.

I then put my boat in the water later that day for some family time and I ran the electronics in my boat. I have two in my boat...Lowrance 104c off the bottom of my bow-mounted trolling motor and a Lowrance X26cHD on the console with 'ducer moutned off the transom. I didn't even lower my trolling motor all weekend. Hell...I never even hooked up the batteries. Never fished from my boat all weekend. Only fished those four hours on Sat morning...from Jim's boat.

I did run my electronics while out pleasure boating with the family and my Lowrance confirmed what Jim's electronics were saying and mine were consistent with his. Mid-day Saturday I saw surface temps at 70 and then on Sunday around 11am, when pulling my boat out of the water, I saw 71 in 4 feet of water by the launch...

LOTS of weed growth in Webster this year. Lots. Which has lots floating silt and particles in the water which are absorbing the sun's heat. They must not be doing the massive weed kills this year on Webster, or...at least...not yet. So far this year, I only know of one weed application being done which was back at the end of April or first of May...around that time. I think by this time last year, they had done three applications that I know of.

The weeds off the end of our pier this year are THICK and heavy. This time last year...it was a clean bottom. Great for the kids swimming off the end of the pier last year. Now, so far this year...the kids aren't too keen on the idea of swimming off the end of the pier...so far...

[Fenski]

Ronski the problem with your tranducer is that you are so cool you affect the water temp just by thinking about going fishing.

[mseybert]

I fished Webster on Saturday. I have 2 lowrance 28cHD units one has a through hull transducer, the other reads through my minnkota terrova universal sonar. I showed from 68-71.

[RonSki]

I had 71-73 last week at Bruce Lake, and 70-72 yesterday at Palestine.

I have two transducers - an Eagle on the trolling motor, and a Humminbird on the transom. They are usually about 1 degree apart, with the trolling motor usually reading higher.
TAN

Thanks everyone! I think the above post from TAN might be the most important part. Could it be possible that since my transducer is only about 6 inches underwater that the top 6 inches is actually COOLER than what's a foot down? I know, dumb question but hey, look at who's asking ;) The only thing that's REALLY messing me up is my Dad is getting the same kind of water temps that I am, and he's got a "big boys boat".

I guess I'm gonna assume that mine is 10 degrees off and try to figure out a way to check it. I have other temperature gages I can use but no idea how accurate they are. I'll work on it, but thanks everyone for heading me in the right direction. Stupid depthfinders...

Ski
P.S. - It's not me Eric, my temp goes UP when I can't catch any fish!

[biddler2]

I have a Terrova US2 connected to a HDS-7 and I had 69-70.4 on Webster Sat. Mine was alittle different then Mseyberts when we checked in the earlier afternoon but not my 10 degrees. The water has been about 4 degrees warmer in the Central part of the state.

[MACK]

Of the three graphs we had in use this past weekend with the three trandsucers, one of those three were on the bottom of a trolling motor.

Yes...I do know that transducers off the bottom of trolling motors will have a slightly different reading, usually warmer, than transducers off the back of transoms. That's due to the black color of the trolling motor down in the water as well as maybe a little bit of heat from the electronics running the motor.

Depending on trolling motor shaft length will depend on how deep that 'ducer is in the water.

This past weekend...with Jim's bow-mounted trolling motor and his transducer off the bottom of that...was barely under the water...maybe...4 to 5 inches at most? The trolling motor that Jim is using off the front of his boat was meant to be a transom mounted t-motor and has a short shaft length. But he's rigged it up to be up front now and even when an adult is standing on the bow of the boat running that trolling motor...the top of his prop will spin out of the water. So..his is not very deep at all.

Ronski...get your boat and your electronics over to Webster asap and tell us what you're seeing with your gear. So far...everyone that has posted here thus far is showing their gear to be pretty much in line with everyone elses, regardless of make, model brand and age......except yours. ;)

[Toad]

I don't really know, I think it matters whether or not you believe the moon is going to crash into the equator Ronski. (Place winking smiley emoticon thingy that I forgot how to make that would indicate inside joke at Ronski's expense, here!)

But seriously, that is a good question. One so good that I would like to elaborate in at least as much detail as Mack. First of all....most of you don't know the backstory on this temperature stuff, but why don't I go into some detail for everyone's benefit.....(don't sleep, there may be a pop quiz on this at the end of the day.)

William Thomson, or 1st Baron Kelvin, or Lord Kelvin, or R-Kelvy as us fans prefer to call him, was an Irish-born British mathematical physicist and engineer. At Glasgow University he did important work in the mathematical analysis of electricity and thermodynamics and was the highest scoring point guard on the b-ball team, who did much to unify the emerging discipline of physics in its modern form, and also led the school to three consecutive final three appearances. (Final Three's, you ask? Well, the history shows that the university of Oxford was banned for recruitment violations for almost a decade, leaving only Glasgow, Cambridge and the North Carolina Tarheels (as usual) in the competition. Word on the street was, that Oxford had purposely ignored the required witch tests when recruiting their squads, leaving many to believe that some of the better players on the team had supernatural powers, including a remarkable player names Magic Yonson, who went on to become a megastar for the times, and who, even later, was drowned, thus confirming he was a witch...or made of rock, take your pick.) He is almost as widely known for developing the Kelvin scale of absolute temperature measurement as he was for the windmill turnaround dunk off a chair move that he invented in the European dunk championships. He was given the title Baron Kelvin in honour (or honor if you are not british and don't feel the need for the placement of unnecessary u's in your words.) of his achievements and is therefore often described as Lord Kelvin, or the Dark Lord of the Sith, or Voldemort, as well as many other names I could probably mention, but won't.......oh and nads,...can't forget Nads, I know I was finished, but that's a great name..Sir Nads. Anyway, the title refers to the River Kelvin, which flows past his university in Glasgow, Scotland.....the first title, I mean, which is the Voldemort one...I think?...

But I digress.....

Anyhoo,..Kelvin found, that at absolute zero, matter contains no thermal energy. Also, the triple point of water is defined as being precisely 273.16 K and 0.01 °C. This definition does three things: 1) it fixes the magnitude of the kelvin unit as being precisely 1 part in 273.16 parts the difference between absolute zero and the triple point of water; 2) it establishes that one kelvin has precisely the same magnitude as a one degree increment on the Celsius scale; and 3) it establishes that when using trolling motor vs fixed mount transducers it is possible to obtain a negative temperature, which is numerically less than absolute zero.

Meaning, in layman's terms,.....the trolling motor transducer may read slightly different water temperature readings, than that of a fixed mount transducer located on the rear of a boat. And also, that readings on say, Lake Webster, may be quite different to that of a reading taken on a lake on the moon Io just outside of the planet Jupiter.

Wait, maybe I should break it down a little for you guys (since laymans terms are probably quite a bit advanced from what you are accustomed to.) Why don't we go with barely able to lift their heads off their necks terms. That should make it easier for all of you to digest a little better. What this all means is that temperature readings are relative....which, actually brings us to Einstein and his famous relativity of muskie fishing theories....

Albert Einstein (pronounced /ˈælbərt ˈaɪnstaɪn/; German: Albert_Einstein_german.ogg ˈalbɐt ˈaɪ̯nʃtaɪ̯n ; 14 March 1879 – 18 April 1955) was an ethnically Jewish[1][2], German-born theoretical physicist who was a talented b-baller in his own right. He is best known for his theor........you know, I'm pretty sure you guys are up to snuff on this dude, given his contribution to our sport, so I'll move on and save this for later, I think.

Anyway, what it boils down to...(get it, boils down to...lol, that's a great temperature reference joke, heh heh heh,...I crack me up, sometimes.) What it boils down to, is that the temperature reading makes no difference. It is always 68 degrees in the water. We just think the temperature is different because our eyes tell us that our depth finders are correct. Only somehow, Ronski has got himself a magical depthfinder that only reads the true temperature of the water all of the time. Simply amazing stuff. Of course, this will all become controversial when Ronski is fishing in August and when all of the rest of our unmagical temperature gauges read that the water temps are in the high eighties, but hey, that's entertainment isn't it?

Anyway, that's the way I look at it......

Beat that Mack!!!!! (I almost cut/pasted the dictionary, but fortunately, I stopped myself and will save that for another time.)

Later I may go into the history of the Double Cowgirl and how Benjamin Franklin was the true inventor of this awesome muskie catcher.....until then, you may now proceed to hang on the edge of your seats in anticipation.

Professor Toad,
or Lord Toad the Grand Inquisitor if you prefer.

[MACK]

Beat that Mack!!!!!




Uhhhhhhhhh,.,,,,,,.......after reading that.....I got nuthin'.

You got me...even by throwing in a Monty Python reference to the witches....that's good stuff man....good stuff. I think you hit the nail on the head and got it dead on.....spot on...nice job. Clear as mud.

An amazing read. But not as amazing as watching a 5'-3", 105 lb cute chick wolf down 12 Blazin Hot Wings at BWs last night in 2 minutes and 35 seconds.....if only we had Ronski's transducer to read the temp of that chick's mouth as she devoured those things......then the real test would have been complete....