Pole Mounted Transom Transducer

[Strider493]

I wanted to mount a new transducer on my boat for deep dropping. I decided to go with the Furuno 38BL-9HR. This is a 2KW, 38 kHz transducer. I have it paired with an FCV 295. I posted some questions a while back and promised to come back and show the installation once I had it done. Hopefully this might help someone else who finds themselves in a similar situation. I have not used it yet in real deep water, and will post an update once I’ve done that.

My problem was finding a spot to mount the transducer. My boat is an old (1991) Hydra Sports 2500. The boat is a little unusual in that I added a fiberglass bracket to the boat around 13 years ago. I replaced the fuel tank a few years back, and while I had the deck opened up, I made some modifications and added a below deck insulated fish box. This used up all of the space in the bilge, so there was no room to mount this transducer in the normal spots. So, my only option for mounting was on the transom of the bracket between the motors, or inside of the bracket. For a couple of reasons, I decided to go with the transom mount, instead of inside the bracket.

My #1 goal was top performance of the transducer and that meant getting it into the cleanest water possible. Since there is a 3 ½ inch step where the bracket attaches to the original stern of the boat, I was not confident that I would get good performance if it was mounted inside of the bracket abaft that step. By mounting it on an adjustable pole, I am able to have it function in the traditional skimming position, and I can also lower it about 6 inches. My hope is that I can use it in the lowered position once I get to my general area and start looking around while trolling at 6 to 8 kts.

Here are some pictures of the process. (All metal materials are stainless steel.)

Fiberglass "box" I made to mount the transducer in.



Showing the pole mounted to the stern of the bracket. I used a rod holder for the upper mount and a 1/8 inch thick SS pipe strap with a PVC spacer through bolted to provide the strength needed. I got nice tight fits in the rod holder and strap by shaping Kydex into them for the proper "shim" thickness. It is tight, but will slide up and down with a little force.



This shows the removeable pin that will allow me to lower it into clean water. The T handle is 3/8 threaded rod covered with silicone tubing.

 

[Deep Blue]

Strider493,

Thank you for sharing these pictures, it's looks like a very professional installation. I'd would like to know when you are trolling between 6-12 knots, what kind of fish targets and performance that you are seeing using that pole mount when using the FCV295 & 38BL-9HR Transducer combination.

Pole mounting isn't a real big option here in the States, but is used pretty extensively over
in Hawaii, Australia, and NZ. And I know of several boats that using the pole mount options for the Survey WASSP.

- Deep Blue

 

[Strider493]

I have not had the boat out in the deep yet to get a feel for its performance, but here is my plan.

I've become a bit obsessed with deep dropping for swordfish off of the Outer Banks of North Carolina the last couple of years. We have managed to catch one swordfish about 100lbs, lost a couple, had a ton of bites, and had some epic tangles while working out our dropping techniques.

One of my issues is that my former FCV 585 marked bottom well down to a little over 2000 feet, but did not do as well as I would like in spotting the deep scattered layer. So I decided to upgrade to this transducer and the FCV295. My SS264 transducers are still installed, so I am using the 200kHz one for the high frequency ducer.

The plan is to get to my general fishing area, slow down to about 7 kts or 8 kts, drop the transducer 6 inches, and then put out a few lines while prospecting the area for some life down near the bottom. (All of our bites have been between 1400 and 1700 feet deep, so I would zig zag along that depth while watching the sounder.)

The area I fish tends to be popular for marlin, yellowfin, and bigeye tuna, with a few mahi around from time to time.

I did take the boat out in the sound yesterday and was surprised to learn that the transducer did fine in it's "skimming" position up to about 20 kts. Considering there is a 3 1/2 inch step 30 inches in front of the transducer, I was real happy with that.

My wife and I will be on vacation down at the Outer Banks in April, so if we get a real nice day, I will be able to make the run and see how things perform. If we do get out, I will take some pics of the sounder at different speeds and let you know how things worked out. The weather is pretty fickle this time of year around here, so it might be a while until I can get out there. During our summer months, it is much more doable in my 25 foot boat.

 

[Deep Blue]

Good Luck out there Strider493, and please let us know how your set-up works for the fishing...

-Deep Blue