Author Topic: 21HT through hull transducer selection help  (Read 735 times)

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Online Mile2885

21HT through hull transducer selection help
« on: February 14, 2017, 12:43:35 PM »
I'm in process of a major electronics and wiring upgrade on my 21HT.  I'll be running the Lowrance HDS9 Gen3, HDS7 Gen 3, 4g Radar/MARPA but was told I'm wasting my time with my old transducers.

Currently I have a P79 shoot through and a P66 off the back.   I can see the downrigger balls when trolling but don't see fish (this was last season pre upgrade). Maybe I'm just fishing in the wrong spot!

I was told I should be looking at the B164 through hull but I've also noticed there is a B175 with several variations. I uderstand that I'll need the 12 degree tilt but the rest is a mystery to me. Planning on doing this once and want it right the first time. Any feedback on what the better unit for Northwest Saltwater fishing would be? Seems like folks have done both but I don't see folks with Lowrance equipment.  Thanks. 

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Online HemiGTX

Re: 21HT through hull transducer selection help
« Reply #1 on: February 14, 2017, 06:33:04 PM »
I don't have any experience with a b164, but If you want to stay with a shoot-thru-hull transducer, you can mount an airmar m260 in the bilge if you don't want to bore holes in your hull. 
AKA: "The guy who fishes with Nicole"

Offline Nineball

SC17, 75etec, T9.9

Online Mile2885

Re: 21HT through hull transducer selection help
« Reply #3 on: February 14, 2017, 08:57:38 PM »
I have a few recommendations for the b175m. Trying to get caught up on my transducer research.  My head is spinning.

Offline Markshoreline

Re: 21HT through hull transducer selection help
« Reply #4 on: February 14, 2017, 09:38:51 PM »
For my through hull went with the  12 degree (medium) b175h serving a Garmin 710xs and it is awesome.
« Last Edit: February 20, 2017, 07:52:05 AM by markshoreline »
2002 Sea Ranger HT 21, Yamaha 150, Yamaha 9.9

Online FishAddict

Re: 21HT through hull transducer selection help
« Reply #5 on: February 15, 2017, 02:57:16 PM »
What do you fish for and how deep?

I have the B175HW and it has been an awesome transducer with a 25 degree cone. Good at marking fish and bait to about 600ft and will read bottom over 1200ft.  It is not good at locating structure since the cone is wider, but fish discrimination from the bottom is fantastic.  The P66 is a 45 degree cone at 50 kHz so I would keep that on the transom for tracking your downrigger balls and either do the b175 hw or b175m for finding bait and fish.  Since you have two gen 3 units you could power two chirp transducers and network them.  Also Airmar is supposed to be coming out with a transom mount P66 version of the 600 watt b75.  They have already released a small(no big tank) in hull version of the b75 & b175 if your not willing to drill the big hole.

P75C-M Broadband Transducer 600 watt

M175C-M  1k

http://www.thehulltruth.com/marine-electronics-forum/791832-airmar-s-new-hull-transducers.html
21ft Sea Ranger w/Yamaha F150

Online Mile2885

Re: 21HT through hull transducer selection help
« Reply #6 on: February 15, 2017, 07:12:01 PM »
Fishing in the Northwest - generally in the San Juans for halibut, salmon, lings, and prawn. I don't mind cutting the hull for the transducer if I need to. I may keep the P66 off the back. I do plan on networking the units. I've gone this far with the electronics upgrade that I don't want my transducer  to be the limiting factor.
« Last Edit: February 15, 2017, 07:16:41 PM by Mile2885 »

Offline Markshoreline

Re: 21HT through hull transducer selection help
« Reply #7 on: February 15, 2017, 09:39:29 PM »
It's helpful to be able to see the shrimp clouds!  Very good detail.
2002 Sea Ranger HT 21, Yamaha 150, Yamaha 9.9

Online FishAddict

Re: 21HT through hull transducer selection help
« Reply #8 on: February 19, 2017, 09:18:57 AM »
Either the b175m or b175hw is going to do what you want.  The higher frequencies will give you more detail.  The wider cone will be better for salmon fishing and showing bait and fish in the water column.  You will see less in the water column with the b175m due to the smaller cone.  Airmar's published specs on the b175m are wrong.  I believe the cone is actually around 10-18 degree's.  The benefit of a smaller cone is being able to get a better picture of bottom structure (for ling and halibut).  I do more searching while salmon & tuna fishing so that's why I went with the b175hw.  I already know the  structure of the bottom fishing spots I frequent.  Either way you'll like the chirp 1k transducer.  I would narrow down which of the type of fish you spend the most time searching for and pick the best transducer for that application. :twocents:
21ft Sea Ranger w/Yamaha F150