# Bottom Finder question



## Gator167 (Jun 23, 2008)

Just a quick question. I have a Furuno FCV-582L bottom finder on my Trophy. The transducer is mounted on the starboard side of the transom, about 1 foot to the right of the outboard. Now I know that once you get up to a certain speed,all sounderswill losetheir depth finding,but mine seems to cut out at about 6to10 mph, which is kinda slow cruising speed. This makes it kinda scary when Im in thebay getting close to shore, as the depths get really shallow really fast. I can slow backdownand about stop and it will reaquire the bottom. 

Do you guys think that maybe the transducer is mounted too close to the motor wash making to lose signal too fast, or is this what everybody goes through? By the way, I love the sounder andwill not replace it at this point.

Thanks in advance

Mike


----------



## lobsterman (Sep 30, 2007)

Yes I think that is the problem. We had a reg 582 on my buddies boat and it read wide open.


----------



## snagem 1 (Sep 28, 2007)

Generally speaking, the closer to the keel, the better the marking capabilities at higher speed.


----------



## Rockbottom (Dec 1, 2007)

After having repowered my boat, (going from twins to a single). I moved my transducer and was having the same problem as you described. It turns out that when I attached my transducer the second time I did not have it low enough.I adjusted it down about a 1/2", to where the transducer was about 1/2" below the hull and the problem was corrected. It went from cutting out at 7 or 8 knots to now reading at up to 40 knots.


----------



## Gator167 (Jun 23, 2008)

Good info..I may try to drop it down into the water a little more and see if it will read better. Either way, if I can just get it to read at about 25 mph, that would be fine.:clap


----------



## The Maintenance Shoppe (Nov 5, 2007)

you should not lose the bottom at any speed going forward. It needs to be properly adjusted.


----------



## X-Shark (Oct 3, 2007)

Look at Fig 10 on page 3



http://www.airmartechnology.com/uploads/InstallGuide/17-247-03.pdf


----------



## Gator167 (Jun 23, 2008)

X-Shark,

Thanks for the link. I think if I shim it just a bit it may do the trick. I will post back when I get the results. It looks like this weekend may be a wash with the wind picking up, so it may be next weekend before I can test it out.

Thanks again guys!:bowdown


----------



## X-Shark (Oct 3, 2007)

I usually set them so the leading edge is real close to 1/4in below the hull surface and the trailing edge is 3/8in below the hull surface.



Now the measurement would be taken on the inboard side of a deeper V hull as it has a large amount of deadrise.



But if you get feeling Froggy I can install a Airmar B-60 thruhull and that will solve your problem and really clean up the looks of your transom.





http://www.airmartechnology.com/airmar2005/ex20/RMProducts/ElectCat.asp?ProdID=36&Man=All&PageNo=67


----------



## Gator167 (Jun 23, 2008)

hmmm The thu-hull tranducer looks interesting. I always see those advertised and think that they are for the really big boats.Call me chickensh!t, butI always worry about drilling a hole in the bottom of my boat!!:boo


----------



## X-Shark (Oct 3, 2007)

Ain't nothing but a thang! I have No problem putting a 2 3/8in hole for a Airmar B-60 in the bottom of a boat.



End of this month I'll be putting a Airmar B-164 1000watt tilted element X-ducer in a 21 Mako. That unit takes a 3 3/4in hole.



Yes it's scary for the armature person to be drilling a hole in the bottom of their boat.


----------



## Gator167 (Jun 23, 2008)

First off, I really appreciate every comment, especially X-Shark with the links he found, as I would love to able to make this thing work correctly without having to take it to the shop. And no, I did not mount this thing wrong, I bought it already installed.:banghead

If you look at these pics, does it look like I can fix the problem by just shimmingthe tranducerat the top to make it point further into the water, or doesthe whole thingneed to be moved closer towards the center of the boat? I was at Harbor View this morning and they have the new ones much closer to the center than mine. If I do have to move it, what will I use to fill in the holes where the old screws were without it looking like crap?


----------



## X-Shark (Oct 3, 2007)

I need a closeup side view of the X-ducer in relation to the bottom of the boat.



Another helpful thing for the pix would be a straight edge laid along the bottom of the hull extending out across the x-ducer.



Your close now.


----------



## Sailor50 (Nov 8, 2007)

I have the same problem, have a Raymarine DS500 with the transducer mounted pretty much like yours. I lose the bottom around 10mph. I rode with someone who had his transducer mounted on centerline (he had twin engines) and he painted the bottom at any speed. In my wisdom, I thought I would remount my transducer on the centerline too, in front of my single engine (Yamaha 250) Well, I could paint the bottom at any speed with it on the centerline but my engine would not work right, bog down, etc. Assumed the turbulence from the transducer in front of the engine was messing up some type of sensor on the engine. Moved the transducer back to where it was and the engine works fine now, and the transducer still loses the bottom around 10 mph. Just pass this on so you don't make the same mistake I did. I guess there is a reason to not mount it too close to the engine.


----------



## X-Shark (Oct 3, 2007)

Yes that will work on a twin motor setup, but will cause water flow problems to a single motor.



Your next step is lowering the x-ducer. I hope is was mounted so you have adjustment?



You also want to have the trailing edge slightly lower than the front edge.



Have a screwdriver with you and pull the boat into shallow water to make any additional adjustments if necessary.


----------



## Gator167 (Jun 23, 2008)

X-Shark, I hope this helps. Ive already moved the boat back on the trailer to try and get x-ducer from sitting on the runner board, but for now it's still sitting on it. It looks like it should be sitting into the water enough, but if I knew the answers, I wouldnt be bugging you guys!


----------



## X-Shark (Oct 3, 2007)

OK It looked to deep at first from the STB side, but then from the Port side it doesn't look deep enough at all. Still hard to tell from the pixs and tape measure as a straight edge.



The fact that it is hitting the bunk could be moving it also. The boat needs to be slid back so the end of the bunk is perfectly even with the transom and then the winch stand adjusted back so that the boat can't go forward to where it is now.





Do you get a router tail coming off of the X-ducer at speed?


----------



## Gator167 (Jun 23, 2008)

Im sorry for being such a novice, but what is a "router tail"?

I plan on setting the boat back as soon as I can put it in the water. I, like you, dont like that thing sitting on the bink, even thoughit is just millimeters away, it is not actually touching the bunk.

Shark, you have been a great help. Thanks man.


----------



## X-Shark (Oct 3, 2007)

My Bad misspelled word. A Roster tail IE: Water spraying up off of it.


----------



## bluffman2 (Nov 22, 2007)

> *X-Shark (10/17/2008)*My Bad misspelled word. A Roster tail IE: Water spraying up off of it.


its spelled roosteroke


----------



## Gator167 (Jun 23, 2008)

Shark, I have noticed a Rooster tail coming from the x-ducer, but that doesnt mean its not doing it. I would take it out tomorrow if it wasnt going to be so dang windy:banghead


----------



## saltwatersteve (Oct 23, 2008)

sounds like you and xshark are on the way to resolving the problem, be sure to look ahead of the transducer to see anything causing turbulance, i.e. thru hulls, chines or steps in hull. Be sure to try using 200Khz or (high freq.)setting, it will normally read better at higher speeds as long as your not in really deep water.

Steve @ offshore electronics


----------



## jkspencer (Apr 23, 2008)

Looks like you've gotten a lot of advice. I have a Furuno FCV-585 (I lovemine too) which came standard with an Airmar transducer. I had lots of problems on my 22-ft Everglades, trying to get it optimally positioned. I'm still not 100% happy with how it reads at speed, but it's a lot better than it was at first. Obviously you can't get too close to the outboard, but you can probably get a lot closer than you might think - it all depends on about a dozen interactive variables which you'd have to be an especiallygifted idiot savant to figure out - LOL. I've got a swim ladder, trim tabs, hi-speed baitwell pickup, a couple of clamshells, another transducer on my Lowrance chartplotter unit on the bottom of my hull, as well as a backwards bronze pickup connected to my fishbox that's a huge design flaw Everglades won't own up to (but that's another story). The deadrise, the shape of the hull, the angle of the boat in the water, and the draft all play a part. First thing to check is the angle of the transducer; thankfully, you can experiment a little without drilling and patching (make some temporary shims and do some tests; think about how your boat rides in the water...if you start to lose signal at speed, it could be that your transducer is angled too far back.) Also make sure it's pointing straight down (as opposed to slightly left or right). Turbulence from the motor can come into play at specific - and unpredictable distances from the prop (kind of like your car experiencing vibrations at certain speeds due to the wheel balancing). Even the pitch of your prop can affect the transducer. Unless you've got a hull that produces an extreme amount of turbulence/cavitation, you should be able to get a good signal at 30+mph in calm water. I can't say about yours, buy my Furuno takes a while to get a signal back once it's lost (which means I'm screwed once the hull leaves the water...gotta' slow down and re-acquire). Oddly, my Lowrance doesn't have that problem (and it uses the EXACT same Airmar transducer as the Furuno - I have to keep them on different frequencies when using both), but the Lowrance bottom definition isn't nearly as detailed as the Furuno. I believe this is one of the most frustrating things about boating - and I had a 'professional' installer helping me (he wasn't able to tell me anything I couldn't figure out for myself). It may take some time and some trial-and-error, but you should be able to get there. In any case, Good Luck and Good Fishing.


----------

