B175M vs TM265LH for Tampa Bay out to 120 feet
#1

Hello there:
Current Electronics Setup on the boat:
Furuno FCV-585 firing an Airmar B164 transducer - this unit has been VERY good to me, marking lots of fish, and reliably reading bottom up to around 20 knots, but the screen has delaminated, so it's the time to upgrade
Garmin 94SV chirp firing a CV51TM transducer - i use this for just chart plotting, but it will be retired eventually, once i get the second TZT3 mfd. for now it will just be for redundant plotting. i haven't had good luck finding any fish or anything with this unit.
Electronics in boxes waiting to be installed when I get home
Furuno TZT12F TZTouch3 MFD + SCX20 Satellite Compass
Furuno DFF3D firing the 165T-TM54 transducer
So I have thought about moving towards a chirp transducer. options I am thinking about:
1) Airmar B175M - uses the same thru hull that my B164 uses. Remove B164, replace with B175HW.
Pros - fits in existing thru hull - no glass work - medium chirp will not interfere with DFF3D operating frequency of 165khz. in many photos provides great images of fish marking and what appears to be hard bottom returns
Cons - single channel chirp does not take advantage of the new MFD's dual channel chirp capability. does not allow accu-fish or bottom discrimination features of the TZT3 internal sounder either.
2) Airmar TM265LH - same elements as B265LH , except transom mount
Pros - easier to mount on transom, no glass work - low/hi chirp allows rez boost, accu fish, and bottom discrimination capability of the TZT3 internal sounder. proven performer for bottom fishing out to 120 feet and deeper, considered overkill?
Cons - transom mounting may reduce bottom holding and marking capability at speed, high frequency chirp will interfere with DFF3D operating frequency, (furuno has a solution coming out later this year to fix this)
3) Airmar B175HW - uses the same thru hull that my B164 uses. Remove B164, replace with B175HW
Pros - almost the same as B175M
Cons - high chirp frequency will interfere with DFF3D until update comes out, in deeper water, will lose ability to pinpoint the bottom due to the wide beam at 25 degrees. may overlap with capabilities of the DFF3D? lose out on dual channel / BD / RB / AF
4) Airmar B175H - uses the same thru hull that the B164 uses
Pros - high freq narrow beam should help pinpoint where to hit spot lock on the rhodan
Cons - same high frequency interference issue, same lack of additional features to take advantage of regarding rezboost, bottom discrimination / accu fish
TARGET SPECIES
anything that cooks up nicely
that I can catch inside 120 feet of water, cause that's about as far out as i'm comfortable going on a typical day, I would say 75% of the time I am inside 75 feet of water...
Snapper, Grouper, Mackerel, Bonitas, Grunts and Porgies, you name it..., Blackfin are on the bucket list lmao
Which of those transducers would you pick and why?
how many of you would say stay with the B164 ?! I understand it's a high Q transducer and it may continue to provide excellent results finding hard bottom with the TZT3 internal sounder even though it's traditional and non chirp...
Current Electronics Setup on the boat:
Furuno FCV-585 firing an Airmar B164 transducer - this unit has been VERY good to me, marking lots of fish, and reliably reading bottom up to around 20 knots, but the screen has delaminated, so it's the time to upgrade
Garmin 94SV chirp firing a CV51TM transducer - i use this for just chart plotting, but it will be retired eventually, once i get the second TZT3 mfd. for now it will just be for redundant plotting. i haven't had good luck finding any fish or anything with this unit.
Electronics in boxes waiting to be installed when I get home
Furuno TZT12F TZTouch3 MFD + SCX20 Satellite Compass
Furuno DFF3D firing the 165T-TM54 transducer
So I have thought about moving towards a chirp transducer. options I am thinking about:
1) Airmar B175M - uses the same thru hull that my B164 uses. Remove B164, replace with B175HW.
Pros - fits in existing thru hull - no glass work - medium chirp will not interfere with DFF3D operating frequency of 165khz. in many photos provides great images of fish marking and what appears to be hard bottom returns
Cons - single channel chirp does not take advantage of the new MFD's dual channel chirp capability. does not allow accu-fish or bottom discrimination features of the TZT3 internal sounder either.
2) Airmar TM265LH - same elements as B265LH , except transom mount
Pros - easier to mount on transom, no glass work - low/hi chirp allows rez boost, accu fish, and bottom discrimination capability of the TZT3 internal sounder. proven performer for bottom fishing out to 120 feet and deeper, considered overkill?
Cons - transom mounting may reduce bottom holding and marking capability at speed, high frequency chirp will interfere with DFF3D operating frequency, (furuno has a solution coming out later this year to fix this)
3) Airmar B175HW - uses the same thru hull that my B164 uses. Remove B164, replace with B175HW
Pros - almost the same as B175M
Cons - high chirp frequency will interfere with DFF3D until update comes out, in deeper water, will lose ability to pinpoint the bottom due to the wide beam at 25 degrees. may overlap with capabilities of the DFF3D? lose out on dual channel / BD / RB / AF
4) Airmar B175H - uses the same thru hull that the B164 uses
Pros - high freq narrow beam should help pinpoint where to hit spot lock on the rhodan
Cons - same high frequency interference issue, same lack of additional features to take advantage of regarding rezboost, bottom discrimination / accu fish
TARGET SPECIES
anything that cooks up nicely

Snapper, Grouper, Mackerel, Bonitas, Grunts and Porgies, you name it..., Blackfin are on the bucket list lmao
Which of those transducers would you pick and why?
how many of you would say stay with the B164 ?! I understand it's a high Q transducer and it may continue to provide excellent results finding hard bottom with the TZT3 internal sounder even though it's traditional and non chirp...
#3
Senior Member

I’m following this. I just removed my 585 from my Contender but left the 164 for now and connected it to my 7610xsv along with the GT-51-TM. Last year I put the B175M on my whitewater and have been very happy with it. I don’t mess with the settings a ton...it stays on medium chirp and I use it from reef fishing out to deep drop.
#4

I'd probably stay with the B164, tbh. Fishing under 75' doesn't require a high end transducer. Many people would probably say that even a B164 is a little overkill for fishing at this depth. Having this paired with your 165T-TM54, is probably a pretty good setup.
If you're set on upgrading to a chirp thru hull, I'd probably add the B175M because you won't have to deal with interference, and you'd have a wider cone than the B175H.
I think the B175H, maybe even the B175HW, is probably the best performing ducer in 75-120' if you can get around the interference problems.
Hopefully Gil will chime in for you.
If you're set on upgrading to a chirp thru hull, I'd probably add the B175M because you won't have to deal with interference, and you'd have a wider cone than the B175H.
I think the B175H, maybe even the B175HW, is probably the best performing ducer in 75-120' if you can get around the interference problems.
Hopefully Gil will chime in for you.
#5
Senior Member

If you are only fishing to 120 feet the 265LH seems to be a massive overkill to me. That is for if you are going offshore. If you can afford it it will work fine but you probably do not need it. And not need to drag an extra TM if you do not need it. Better to use the existing through hull.
The 1KW L is for deep dropping, down to 3,000 feet.
At your depths you are probably best served by a B175H or HW (depending on if you want a wide or narrow beam) or a B175M if interference is an issue.
I mean if you did install both a TM265LH you will have more than enough coverage for what you want, but you will have an offshore set up that can work in shallow waters.
What type of boat is this?
The 1KW L is for deep dropping, down to 3,000 feet.
At your depths you are probably best served by a B175H or HW (depending on if you want a wide or narrow beam) or a B175M if interference is an issue.
I mean if you did install both a TM265LH you will have more than enough coverage for what you want, but you will have an offshore set up that can work in shallow waters.
What type of boat is this?
Last edited by GregMachy; 01-15-2021 at 01:43 PM.
#7
Senior Member

I just think it would be a waste to get Furuno electronics and then get a transducer that didn't support bottom discrimination, especially for someone fishing offshore Tampa where it's all about locating hard bottom. Here's a compatibility matrix that will show you which transducers support which features: https://www.furunousa.com/-/media/si...ity_matrix.pdf
#8

I just think it would be a waste to get Furuno electronics and then get a transducer that didn't support bottom discrimination, especially for someone fishing offshore Tampa where it's all about locating hard bottom. Here's a compatibility matrix that will show you which transducers support which features: https://www.furunousa.com/-/media/si...ity_matrix.pdf
In that case, should I also be considering the B60 , as it is a direct replacement for the B164 hole in my hull, and it is AF/RB/BD compatible, even though it's only 600 watts?
#9
Admirals Club 


Marine Advertiser

The B164 is 3 7/8"....the B60 is 2.375"..so some filling is needed.
Another option to look at is the Airmar SS265N.....( same hole as the B164) ......The same broad band element....as found on the 200K side of the B260.
#10
Senior Member

I think so, considering 120' is max depth you might fish, but I am no expert on this, definitely get some other opinions or do further research. I have a B60 with a Furuno gp1971f, I fish west of Pinellas County, and I really like the bottom discrimination feature, it puts finding hard bottom on easy-mode. But maybe a more experienced person doesn't need the bottom discrimination and can read the returns fine on their own.
The downside is the B60 doesn't chirp. Some people say the RezBoost feature is almost as good as CHIRP. For fishing out here it seems finding hard bottom is more important than getting clear fish echoes, I don't really know if I'm missing anything important by not having CHIRP.
The downside is the B60 doesn't chirp. Some people say the RezBoost feature is almost as good as CHIRP. For fishing out here it seems finding hard bottom is more important than getting clear fish echoes, I don't really know if I'm missing anything important by not having CHIRP.
#11

is this compatible with resboost, bottom discrimination, and accu fish ?
#12
Senior Member

The thing about the TM275LHW is it is pretty huge, so if you will never go out deep, you might not want something that big on your stern. It would only really be for if you do plan to venture offshore.
And it is definitely a massive overkill for 120 feet water. It would probably make most sense to get something that fits your existing transducer through hull.
#13

Well you could actually take that a little ways out in good weather, and get to pretty deep water, but it is not a huge boat.
The thing about the TM275LHW is it is pretty huge, so if you will never go out deep, you might not want something that big on your stern. It would only really be for if you do plan to venture offshore.
And it is definitely a massive overkill for 120 feet water. It would probably make most sense to get something that fits your existing transducer through hull.
The thing about the TM275LHW is it is pretty huge, so if you will never go out deep, you might not want something that big on your stern. It would only really be for if you do plan to venture offshore.
And it is definitely a massive overkill for 120 feet water. It would probably make most sense to get something that fits your existing transducer through hull.
Yeah i mean, if i had a guarantee of near glass seas, i would have no problems going out 50 miles! but i just don't see that happening lmao
#14
Junior Member

Hi Mattology,
I’m going through exactly the same scenario on a new build now. I’ve decided to go with the B175HW as I’m confident it will hold at high speed and between that and the DFF3D should be able to find the fish. but I would like the AF and BD features, so am tossing a B60 in the mix as well. they’re cheap but should add some features when trolling along at less than 10 knots.
I don’t believe the 265LH has BD and RB, just AF. But I guess if you program it as a B260 it might work for those. But I agree with the other members, likely overkill for you.
I’m going through exactly the same scenario on a new build now. I’ve decided to go with the B175HW as I’m confident it will hold at high speed and between that and the DFF3D should be able to find the fish. but I would like the AF and BD features, so am tossing a B60 in the mix as well. they’re cheap but should add some features when trolling along at less than 10 knots.
I don’t believe the 265LH has BD and RB, just AF. But I guess if you program it as a B260 it might work for those. But I agree with the other members, likely overkill for you.
Likes:
#15
Admirals Club 


I have the B175hw on my Garmin 8610s and it works awesome. Transom mounted transducers do not read well when the boat is moving. However, I have both.
#16
Senior Member

I like RC585's idea. Keep the B164 for now, add a B60 along with the DFF3D. When you add your 2nd TZT3 in the future, if you feel like there is something specific you are missing out on, replace the B164 with whichever B175(M/H/W) would best fill in whatever that gap is.
#17

Hi Mattology,
I’m going through exactly the same scenario on a new build now. I’ve decided to go with the B175HW as I’m confident it will hold at high speed and between that and the DFF3D should be able to find the fish. but I would like the AF and BD features, so am tossing a B60 in the mix as well. they’re cheap but should add some features when trolling along at less than 10 knots.
I don’t believe the 265LH has BD and RB, just AF. But I guess if you program it as a B260 it might work for those. But I agree with the other members, likely overkill for you.
I’m going through exactly the same scenario on a new build now. I’ve decided to go with the B175HW as I’m confident it will hold at high speed and between that and the DFF3D should be able to find the fish. but I would like the AF and BD features, so am tossing a B60 in the mix as well. they’re cheap but should add some features when trolling along at less than 10 knots.
I don’t believe the 265LH has BD and RB, just AF. But I guess if you program it as a B260 it might work for those. But I agree with the other members, likely overkill for you.
I've decided that if i can find a place for this monster of a transducer to fit, i'm going to go with the 165T - 265LH PM488, and sell off my transom mount DFF3D transducer as well as the other stuff i won't need anymore. Is it overkill? yes. Does it give me a reason to road trip to the east coast and to the keys and fish some other places now that i'll have the electronics ? sure!
Likes:
#18
Senior Member

the 265 does support it natively:
Attachment 1122985
I've decided that if i can find a place for this monster of a transducer to fit, i'm going to go with the 165T - 265LH PM488, and sell off my transom mount DFF3D transducer as well as the other stuff i won't need anymore. Is it overkill? yes. Does it give me a reason to road trip to the east coast and to the keys and fish some other places now that i'll have the electronics ? sure!
Attachment 1122985
I've decided that if i can find a place for this monster of a transducer to fit, i'm going to go with the 165T - 265LH PM488, and sell off my transom mount DFF3D transducer as well as the other stuff i won't need anymore. Is it overkill? yes. Does it give me a reason to road trip to the east coast and to the keys and fish some other places now that i'll have the electronics ? sure!
#19

Furuno explicitly says they do not support the M265LH or the TM2645LH because they have not been specifically tested.
Airmar specifically calls out the M265LH and TM265LH as having the exact same discrete elements as the B265LH, and being capable of the exact same bottom discrimination signal processing that the B265LH is capable of doing. The M265LH and TM265LH transducers were released AFTER the B265LH.
According to AIRMAR, the following transducers are capable of all of the same technologies :
B265LH
PM265LH
CM264LH
TM265LH
M265LH
However I have not had the greatest luck finding anyone who is successfully using the TM or M versions with the accu fish, resboost, and bottom discrimination.
My thoughts are, and this not having any formal schooling on RF and eMAG since my senior year getting my BSEE... the M265 will receive some amount of attenuation through a fiberglass hull. I am not sure what amount that will be. Perhaps it may not work well out to 1000 feet anymore. I think it would still work totally fine at 250 feet, or hell, maybe deeper. But it is expensive to field trial it and have it not work. . but believe me, i've been thinking about it. I just wonder about the in hull transducer overheating or something. I would consider running a larger tank of antifreeze / mineral oil for it, or incorporating a sort of radiator or passive cooler to keep the transducer cool while running.. and at that point, is the amount of work the same as just properly installing a flush mount thru hull with the right glass work?
It wouldn't be the first time I've gotten something like that to work.
it is one of those things I didn't bother asking on THT because I didn't want to be ridiculed like i've seen happen to so many on here.
#20
Senior Member


I find I use the wide cone 50k of the TM260 more than Axiom high CHIRP of the RV100.
These transom mounts are large but not that much bigger than the various 3 in 1 multi imaging transducers.
Below is a side by side with 50k on the left and high CHIRP on the right. Some preditor on an anchovy school.

Next pic is 50/200 of TM260. Axiom high CHIRP pings constantly causing noise on the 200k return. Not really bad but this cone is narrow and I don't use it much.

I hope these side by side comparisons help you with your decision.