Hobie Revo Rigging

I had trouble with my pro Angler, I tried to install a transducer right behind Mirage Drive and glued inside hull. I thought I did a crappy job gluing because I could barely read the screen, ripped it out, re-installed same location, same problem. Ripped it out again, hung the TD over the side, got decent readings when sitting still, then held the "arm" I made to hold the TD in a temporary location and noticed that when underway, the flippers and the bubbles messed with the signal. I mounted it temporarily under the bathtub bucket up under the front hatch, no more problems. But when my new Lowrance HDS-5 came in, the transducer was GIANT and needed to be immersed in water and a clear view on both sides, so I mounted it on a kick-up mount externally like my Bass boat has on the stern behind the rudder. Being that far away from the Mirage Drive I get NO interference, but I have to watch shore landings. I'll take some photos and post them soon. I have the Side imaging unit and 2-7amp batteries below deck in a portable case so I can swap the head unit and the side scanner between boats.

On my Whaler, I had a scrape in the hull just forward of the transducer, and it created enough turbulence to make my screen unreadable on plane. I moved the transducer to other side of outboard motor... no more clutter. I think it is the air bubbles the flippers create more than the flippers in the cone, but i could be wrong. I know moving it in front helped a lot.

Great observations, troutnut.  Thanks.  

grease seems like it could become a messy nightmare over time or on a really hot day.

A Google search shows a grease mount is not uncommon.

High temp, marine grease.  Holds its viscosity at high temps, and water resistant.  "high temp" has a drop point over 300C.  (DP is the temp at which the grease becomes liquid).  Even lower temp greases have DPs over 200C.  I'm going to risk it.  If it turns out to be a mistake, I'm not too proud to admit it and report it.

Update: Outdoor Emporium: $3.99 for a tub of Marine Wheel Bearing Grease (calcium sulfonate complex) (high temp, water-proof)

I'm very interested in how that works out.  I wouldn't mind replacing my water with grease and not having to refill it every couple hours on warm days and every time I go out.

Good idea!

Had the boat out on the Sound yesterday for about 5 hours.  My first task was to see if the mirage drive interferes with the transducer which is mounted just rear of the drive cutout.

As TroutNut previously stated, the answer is yes.

Here is a screen shot.  It shows 4 sections, peddling, not peddling, peddling, and not peddling.  When not peddling the flippers were up.  As I watched the FF throughout the afternoon it seemed that slower peddling created more interference, and at times i could see an interference spike instantly as I started peddling.  

I also installed the drive seal as TroutNut suggested.  It makes a tight fit that will stop water from surging through the rear part of the drive cutout.

My plan now is to move the transducer rearward, under the seat.  The drive flippers project 16" below the boat.  In order to stay out of the 60 degree transducer cone the transducer needs to be at least 9.25" away from the rear edge of the rear flipper.  The rear edge of the crotch hatch is 15" from the rear edge of the drive cutout.  An inch or so farther back is still easily accessible and out of the way of the hatch.  I'll fill the foam with grease and move the battery into a gear bucket in the rear hatch.  I don't want to put the transducer forward of the drive because it is the only useful internal storage location on the boat and I use the forward hatch area for cart wheels and a dry bag.

A quick follow up to the PVC bar mount on the Revo.  The PVC was too soft and had issues, so I replaced it with 1-1/8" aluminum tubing.  Still used stair tape for added security under the Hobie Outrigger Mounts, the RAM ball mount, and the Scotty bar mount.  They are VERY secure now. 

I was surprised at how hard it was to find a scrap piece of Al tubing.  My favorite scrap yard on 4th Ave S in Seattle appears to have been bulldozed.  Pacific Iron and Metal doesn't have a retail scrap yard and Alaskan Copper and Brass didn't have anything in their scrap section.  Found this company in Ballard and ordered/paid online with pickup at Will Call.  They also ship. 

http://www.onlinemetals.com/

I'm very interested in how that works out.  I wouldn't mind replacing my water with grease and not having to refill it every couple hours on warm days and every time I go out.

Good idea!

If you're having to refill every couple of hours you either used the wrong material or didn't seal it well when you did your install.  I find that one fill will last me an entire weekend if I don't have to flip the boat over.

The thought of using grease scares me.  I can imagine what a mess my hull would be if the ducer popped out during transport.

-Spot-

I mounted my closed cell foam transducer holder on my Revo just behind the post near the front hatch. No clutter/interference at all. Also use just H20 in it. Lasts all day, no problemo. Used Marine goop to seal to the yak and also the sides of the outer foam. Tried vaseline on my other yak once and will never do again. It's a mess.

I agree with Spot here.  Grease just sounds too messy for my liking.

I gooped the shizzle out of my closed cell foam puck and made my tranducer hole tight on three sides and made a weep hole on one side to allow bubbles to rise and escape.  For filling the puck with water, I stole a plastic syringe from the wife's pet care drawer, and made a 4-5 inch screw on extention out of some tube laying around the garage.  Once I launch into say a lake, I just pull some water into the syringe, and squirt it in the puck.  Then just slowly lift the ducer once or twice to let the bubbles out. Add just enough water to completely surround the ducer.

Done!  Until next trip out. 

Sometimes I learn from others' mistakes; sometimes I don't.  I'll let y'all know how the grease works out.

    I'm courious, what is it thats mounted/instaled under the center hatch?  Bait tank switches maybe?

    I'm courious, what is it thats mounted/instaled under the center hatch?  Bait tank switches maybe?

To what number post/photo are you referring?  I don't see any photos with the center hatch open. 

I think you might be over-thinking this DN. I can't really see any problems from your screen shot that would effect fishing. I've had my trans right in front of the sail mast tube for many a moon and I've yet to have interference that I'm aware of. And when you really get down to it, there's a lot of other considerations that will get fish in the yak faster than the FF.

Z

  Sorry, The hatch was shown open, it  flashed by quickly during the video at 1:02 min. mark (Maybe a second or two around that time mark) I had to pause and move video cursor to that time to get the photo.  It shows a small box (maybe 1" X3 3.5") with what appears to be 2 buttons, and a cable extending down into the hull.  Wasn't able to determine if what ever it is protruded exterior on the hatch cover though.

I used grease in the closed-cell foam ring around the transducer and tested it yesterday.  For whatever reason I got a faint bottom return and had NO returns between the boat and the bottom.  At 133' the bottom was lost yet it reappeared a couple hours later at 270'.

Filling the foam was not messy using care and a plastic spoon.  Have plenty of paper towels to keep your hands clean and immediately clean up any spillage.  I used way TOO MUCH grease and after trying to stuff the transponder into the foam I removed most of the grease.  I still think I used too much grease and perhaps got a big void under it.  It may still work if little enough grease is used.  The problem is that while excess water will squirt out around the transducer, the grease is too thick.  My plan now is to remove almost all of the grease except about a tablespoon.  All that is needed is enough grease to fill the space formed from the contour mismatch between the bottom of the transducer and the hull when the transducer is pressed against the hull.  That really can't be more than a few milliliters.  I may simply coat the bottom of the transducer with 1/8" of grease then press it into the foam.  

I'll post any progress.

You gonna go with marine goop next time?

Has anyone else used Marine Goop to glue down a transducer then successfully removed it?  It seems that the goop only need be a thin coating on the bottom of the transducer, and a foam reservoir is not needed except as protection.   I don't really care about goop residue on the hull.  I moved the foam reservoir once and while it took some force to pull it off the Marine Goop it wasn't hard.  The entire point of using the grease is to create a maintenance-free installation.  I'm seriously considering this now if the second attempt with less grease doesn't work.