With my thru hull tranny mounted in a performance fairing, I hold bottom at 35 knots in chop. Sure makes finding new ground easier. Transom mounts always a compromise but there are ones that work very well.
I've got a 16ft ally with ribs on the bottom of the hull and after many attempts have finally found a better location. Had to put it deeper down but now throws out a big rooster tail, waiting for it to get ripped off one day now tho haha. So now gonna look into putting a ally plate or something over the top too keep the roster tail down.
You need to fiddle with it Peter ;) Drop the tranny down a few mm or with mine it was the angle approach in the water. My tranny was supplied with angle shims, so basically put one in and I can now read a fairly good pic at 25 knots. Saying that you'll probably miss anything good at that speed.
Do you remember what angle shim you used? Maybe that's my problem as I have the same shape hull as you just a bit smaller. Also from memory you have the furuno 585?
Yeah Paul, 585 with TM260 1kw tranny. The shims came with the tranny pack. I have it lowered to 5mm below the transom line not 3 as recommended and then 1 shim plate. It throws out a bit of a rooster tail but who cares I'm looking forward when I drive lol.
make sure it's between the ribs not behind one. Before moving it at all get someone else to drive the boat as they increase speed (start at a slow speed where you have a good reading) look over the back and take note of what water the transducer is in - is it a clear blue green or full of bubbles/turbulence from the bottom of the hull. then once you start to get to 15Kn+ and lose the picture is there any difference as far as turbulence the tranny is running through. Bubbles of air will affect the reading and this can also be the problem. then tackle the depth/angles as above.
But it has to be pretty flat to do that sort of speed, I know that mine reads at wot in glass off conditions and that is over 40
But in any sea that I might be out on it reads perfectly even in short chop, the heavier engine I just installed actually appears to make it read even better, my transducer is transom mounted and 5mm below, throws a bit of a tail but would rather it reads the way it does
Vinesh87
Posts: 2751
Date Joined: 02/04/11
Depends on the conditions
Depends on the conditions really. In good conditions i see 25kt no worries. In the slop it seems to be down about 20kt.
Prop cavitation, etc etc
JohnF
Posts: 2836
Date Joined: 07/07/10
Its all about the transducer
Its all about the transducer location and installation Peter, almost nothing to do with the head unit.
Lots of info on here, but if transom mounted, then depth and angle are key.
Boston Whaler 235 Conquest......getting the flogging it was built for.
JohnF
Posts: 2836
Date Joined: 07/07/10
With my thru hull tranny
With my thru hull tranny mounted in a performance fairing, I hold bottom at 35 knots in chop. Sure makes finding new ground easier. Transom mounts always a compromise but there are ones that work very well.
Boston Whaler 235 Conquest......getting the flogging it was built for.
jng
Posts: 488
Date Joined: 03/08/07
My tm260 on my furuno picks
My tm260 on my furuno picks up the bottom clearly at WOT, aprox 35-38knots as John said tranny location and angle is the key for transom mount
Paul_86
Posts: 1449
Date Joined: 27/03/09
I've got a 16ft ally with
I've got a 16ft ally with ribs on the bottom of the hull and after many attempts have finally found a better location. Had to put it deeper down but now throws out a big rooster tail, waiting for it to get ripped off one day now tho haha. So now gonna look into putting a ally plate or something over the top too keep the roster tail down.
sea-kem
Posts: 14857
Date Joined: 30/11/09
You need to fiddle with it
You need to fiddle with it Peter ;) Drop the tranny down a few mm or with mine it was the angle approach in the water. My tranny was supplied with angle shims, so basically put one in and I can now read a fairly good pic at 25 knots. Saying that you'll probably miss anything good at that speed.
Love the West!
Paul_86
Posts: 1449
Date Joined: 27/03/09
Do you remember what angle
Do you remember what angle shim you used? Maybe that's my problem as I have the same shape hull as you just a bit smaller. Also from memory you have the furuno 585?
sea-kem
Posts: 14857
Date Joined: 30/11/09
Yeah Paul, 585 with TM260
Yeah Paul, 585 with TM260 1kw tranny. The shims came with the tranny pack. I have it lowered to 5mm below the transom line not 3 as recommended and then 1 shim plate. It throws out a bit of a rooster tail but who cares I'm looking forward when I drive lol.
Love the West!
Paul_86
Posts: 1449
Date Joined: 27/03/09
Haha good point!
Haha good point!
SEAFORCE CORAL BAY
Posts: 150
Date Joined: 09/12/13
Geez guys. 35-38 knots.Doing
Geez guys. 35-38 knots.
Doing well to see much at those speeds, just don't get too distracted by the sounder while cruising that quick.
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Paul H
Posts: 2104
Date Joined: 18/01/07
make sure it's between the
make sure it's between the ribs not behind one. Before moving it at all get someone else to drive the boat as they increase speed (start at a slow speed where you have a good reading) look over the back and take note of what water the transducer is in - is it a clear blue green or full of bubbles/turbulence from the bottom of the hull. then once you start to get to 15Kn+ and lose the picture is there any difference as far as turbulence the tranny is running through. Bubbles of air will affect the reading and this can also be the problem. then tackle the depth/angles as above.
Good luck
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sunshine
Posts: 2555
Date Joined: 03/03/09
My 585 reads perfectly at over 30
But it has to be pretty flat to do that sort of speed, I know that mine reads at wot in glass off conditions and that is over 40
But in any sea that I might be out on it reads perfectly even in short chop, the heavier engine I just installed actually appears to make it read even better, my transducer is transom mounted and 5mm below, throws a bit of a tail but would rather it reads the way it does