Go Back  The Hull Truth - Boating and Fishing Forum > BOATING FORUMS > Marine Electronics Forum
Reload this Page >

Is a thru hull transducer way overkill for a 20' Grady??

Notices
Marine Electronics Forum

Is a thru hull transducer way overkill for a 20' Grady??

Old 04-05-2005, 04:15 PM
  #1  
Member
Thread Starter
 
Join Date: Mar 2003
Location: home port, Salisbury, Ma.
Posts: 99
Likes: 0
Received 0 Likes on 0 Posts
Default Is a thru hull transducer way overkill for a 20' Grady??

We just spent a ton of dough on a new Furuno chartplotter/fishfinder and are wondering which transducer , and which type to use. I have gone back 15 pages in this forum and read all postings on this subject. I'm still not sure what I want. I think everyone agrees that the fishfinder is only as good as the transducer. Iwant full reception at 30 knots and I want to see my jig or peanut shells fall to the bottom as I drop them when fishing. So, is a thru hull transducer way overkill on this little boat?? As far as the mounting I think I can handle cutting the fairing block (out of teak I assume) drilling the hole plumb and mounting the thing. What do you guys think? I'm all ears... ;? ;? ;?

Old 04-05-2005, 06:01 PM
  #2  
cjd
Senior MemberCaptains Club Member
 
Join Date: Oct 2001
Location: Severna Park Md
Posts: 4,275
Received 257 Likes on 148 Posts
Default RE: Is a thru hull transducer way overkill for a 20' Grady??

I opted for a transom transducer for my 18, but i don't fish too deep. I havn't installed it yet, but I will follow your thread with interest. I think its all about how deep you fish. We seem to be huge fans of overkill on this board, but if you can afford it, why not

The new Airmer angled thruhull sounds real interesting and is not too pricey. I know Jim at By owner electronics (forum sponsor) just got them in and will give you great advice, as ell as a great price.

chris
Old 04-05-2005, 06:26 PM
  #3  
MemberCaptains Club Member
 
Join Date: Dec 2003
Location: northport ny
Posts: 90
Likes: 0
Received 1 Like on 1 Post
Default RE: Is a thru hull transducer way overkill for a 20' Grady??

I've had 6 boats with thru hull tducers. From 28-42 footers and each worked pretty well. I've had 2 boats with transom mount and 1 that ATTEMPTS to shoot thru the hull. Both don't work worth a sh. I let the yard talk me out of a thru hull tducer when I bought a Seapro 21. The damn thing never works on plane. The only one to get is the one you want, through the hull.
Old 04-05-2005, 07:34 PM
  #4  
Admirals ClubCaptains Club Member Admiral's Club Member
 
Join Date: Dec 2002
Location: Tallahassee Florida
Posts: 473
Likes: 0
Received 13 Likes on 6 Posts
Default RE: Is a thru hull transducer way overkill for a 20' Grady??

I just installed the Airmar tilted element ducer on my 20' Hydra-Sports. I had a transom mount but had to move it due to adding trim tabs. I've only had the boat out once since installing it, but I really like it. Easy installation with no fairing. There are a few recent threads on this ducer.
Old 04-05-2005, 07:45 PM
  #5  
Senior MemberCaptains Club Member
 
Join Date: Mar 2005
Location: Sanford, North Carolina
Posts: 1,483
Likes: 0
Received 0 Likes on 0 Posts
Default RE: Is a thru hull transducer way overkill for a 20' Grady??

My experience taught me this depends on how deep you're fishing. I have a shoot thru the hull and in Florida (where you can get to 100 fathoms within a few miles) I lost readings in about 300' of water. There are other conditions you need to consider with a shoot thu hull arrangement.. if there is air bubbles or hollows in the fiberglass you're subject to poor readings. My advise... go thru the hull... it doesn't matter what size boat you have. Hope this helps
Old 04-05-2005, 08:21 PM
  #6  
Senior MemberCaptains Club Member
 
Join Date: Jun 2001
Posts: 3,069
Received 7 Likes on 6 Posts
Default RE: Is a thru hull transducer way overkill for a 20' Grady??

Just installed a Garmin 250 FF w/dual range ducer that came with it.
I mounted in IN the hull w/slow-cure epoxy. Is a transom mount transducer and I mounted it to
shoot-through. 22' Biddison
Works great. Never lost the bottom even at 38mph.I'll never get in water over 200'
Old 04-05-2005, 10:02 PM
  #7  
Senior MemberCaptains Club MemberPLEDGER
 
Join Date: May 2002
Location: Skaneateles, New York
Posts: 5,483
Likes: 0
Received 2 Likes on 2 Posts
Default RE: Is a thru hull transducer way overkill for a 20' Grady??

First of all, use something to test the FF other than peanut shells (jig is OK); suggest a penny or a sinker. I'd look at the AIRMAR 256 or 260. We just installed a R99.
Old 04-08-2005, 07:53 AM
  #8  
Senior MemberCaptains Club Member
 
Join Date: Jun 2003
Location: East Central Florida
Posts: 7,319
Received 683 Likes on 322 Posts
Default RE: Is a thru hull transducer way overkill for a 20' Grady??

THe Airmar tilted element transducer would be perfect for you. Benefits of a standard thru with no fairing block or fiberglass work. See this thread:

http://thehulltruth.com/forums/threa...=41702&start=1
Old 04-08-2005, 08:24 AM
  #9  
Senior MemberCaptains Club Member
 
Join Date: Feb 2001
Location: West Virginia
Posts: 3,877
Likes: 0
Received 2 Likes on 2 Posts
Default RE: Is a thru hull transducer way overkill for a 20' Grady??

Lots of success stores with different types of transducers in different hulls placed in different positions, matched with different fish finders, operating on different bodys of water, in different conditions, after being put in place by different installers. Also lots of stories of failure with different types of transducers in different hulls placed in different positions, matched with different fish finders, operating on different bodys of water, in different conditions, after being put in place by different installers.

So tell me something - how valuable is the information?

It is my guess that the biggest reason that many transducers do not perform as expected comes from poor instillation. It doesn't make much difference which transducer you pick if its in there wrong.

Here is another observation. I own a couple of grinders, one of which always has a 36 grit wheel on it. It is a wonderful device for exploring fiberglass in depth. If you take one of those things and pick a spot on any fiberglass boat and start grinding a circle right though it - hull, topsides, wherever - it is not likely that you will encounter a single air bubble on your way through. You find them at the interface where the gelcoat meets with the substrate sometimes, but not even all that often in that location. I've done this on old Bayliners and not seen bubbles - so how many do you think are in the typical Grady?

Thru hull transducers work the best.

In hull transducers work second best.

Transom mounted transducers are least likely to operate at speed.

Thru hull transducers are the hardest to install.

In hull transducers are the easiest to install

Anyone with a screwdriver and a drill can attach a transom mount transducer but no one can tell you how well its going to work at almost any speed above no-wake until they try it out.

Peanut shells? Do you plan to fish at the zoo? Forget all those silly little parlor tricks. Take the boat out over a reef and start looking for fish, leave the peanuts at home.

If you've read back 10 pages you've probably seen a lot. What's rarely said is this - whichever type you choose mount it such that it is pointing either straight down (in two planes) or slightly (not more than about 5 degrees) forward of straight down. It is just as important with an in-hull as it is with a thru hull.

But to answer your original question; no, a thru-hull is not overkill on a 20 foot boat, or any other boat for that matter. Just mount it off the the side a little bit, but not too far (shoot for within 18" of the centerline) off to the side. Mount it on the Starboard (right as you face forward) side. If your boat is on a trailer make sure it is situated as usual on the trailer (not crooked or otherwise supported in an unusual manner) when you do the instillation. Boats always go on the trailer the same way and the same distance if they are landed properly and so if the transducer can't hit anything on the trailer the first time it won't hit anything on the trailer the next couple of thousand times its loaded or unloaded either.

And now the bottom line, and it should be reassuring. Thousands of fish finders are sold every day and many of them are installed by people who have never done it before and are armed with no better information than is included with the Owner's Manual - and they work just fine. Worry less and enjoy more.

Thom

Take your pick.
Old 04-08-2005, 09:41 AM
  #10  
Senior MemberCaptains Club Member
 
Join Date: Dec 2002
Location: Orlando
Posts: 3,997
Likes: 0
Received 0 Likes on 0 Posts
Default RE: Is a thru hull transducer way overkill for a 20' Grady??

No peanut shells but here's a lowrance 104c coupled with a B256 thru hull. The arch dropping down on the left is the bait dropping to 80 feet with surface fish trying to catch it and eventualy giving up and the arch in the middle is a hog yellowtail snapper coming up to join us for lunch. The B256 is the better xducer for 200khz fishing. It will let you see separate bait fish rather than a solid glob.


This is what a school of red snapper looks like when they swam in the shape of a xmas tree. You can actialy see separate fish which is impossible with standard performance xducers.





Old 04-08-2005, 09:46 AM
  #11  
Senior MemberCaptains Club Member
 
Join Date: Dec 2002
Location: Orlando
Posts: 3,997
Likes: 0
Received 0 Likes on 0 Posts
Default RE: Is a thru hull transducer way overkill for a 20' Grady??

One other point. The airmar tilted xducer is not a high performance xducer. it will not give better returns than the typical transom mounted units.

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are On
Refbacks are Off


Thread Tools
Search this Thread

Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service - Do Not Sell My Personal Information

Copyright © 2018 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.