Fish finders

[Andrew]

2020 and the technologies are racing ahead.

Now looking to buy a fish-finder, but have never owned or used one before.

Did a bit of reading up last night and seems like the lower end ones would meet Navigation requirements for cruising an Investigator.
I'm not that interested in fishing, just want to know how deep it is in tidal estuaries, especially when going to anchor for the night. And nice to see a digital depth and speed log reading on it, and nice to see obstructions/rocks etc on the bottom.

Will probably put a transducer into a siliconed pipe against hull. There are already two spots to do this on Teria , both at the front end of each cockpit lazarrete. (made by previous owners, for old departed nav gear..they cut through the floor, excavated the foam floatation to expose hull and put thru hull fittings in there)

I read that turbulence messes up the signal, as the transom gets plenty of that, it may rule out that option. The positions in the hind quarters would be well below waterline and turbulence levels when sailing hopefully.

Also read that simple transducers are one channel 200Mhz for shallower depths. But for a bit more $ dual frequency 50/200Htz transducers can look allot deeper (50Htz gets more depth) Its surprising how deep even the most basic models can detect bottom (eg 750 ft!). The shallower models also consume less power.

Any thoughts?

[Andrew]

Bought a "Garmin Striker +4 fish finder with dualbeam"

It's an entry level one. cost $200 at BCF with club membership. It is designed for kayak and tinny fishermen, is the lowest end of Garmin ff's. but a quality product and capable of sounding to 820 feet maximum in saltwater (1,700 ft fresh) as it has a dual-frequency transducer (77/200 Khz, transom mounted). None of my sailing will be over 150 ft deep. The dual frequency gets good shallow and deep results. Has CHIRP sonar

I will mainly need it for shallow anchor depth waters of 10-50 feet. It has fish finding and conventional echo-sounder displays.
Also can create its own contoured bathymetic charts of an anchorage (or fish spot) and waypoint marking/ navigation..Here is a review (also compares with older striker4) https://fishingmood.com/garmin-striker-plus-4-review/

Noticed it has a battery voltage level readout, sea temperature, and depth / anchor alarms too. It has a power cable that connects to the boats 12v battery (no internal batteries)

No marine charts/chartplotter (the dual depth sounder/chartplotter's are over $450 into thousands of dollars) designed for great depths/ fishing, and need allot more 12v power) (Garmin has a GPS chartplotter/sounder combo called "Echomap 45+CV" for $430-$500)

The other ff at bcf i looked at was a Lowrance Hook4x GPS ff, it was aimed at same kayak/tinny market and cost $150 club price .. It had a single freq 200Khz transducer and no CHIRP sonar. its shape was wider horizontally better for fish view scrolling, so shape was squarer, could've mounted where my old Navman ff was on the cabin bulkhead (the garmin is taller and narrower vertically).

[Watto]

Andrew,

How’d you go with the mounting. Interested if you have any pics.

[Peter T]

Hi all, I have been looking at a Garmin UHD45cv (around $800), because it has the addition of coastal navigation maps as well as the ability to talk to a tiller auto pilot. Does anyone have one of these and especially, does anyone have experience of driving a tiller pilot with one ?
It looks to me like it uses WIFI to communicate ? Not real sure yet how that goes with say an ST 2000 ?
Thanks

[Andrew]

Andrew,

How’d you go with the mounting. Interested if you have any pics.

Gday Luke, I built a thwart to form a bridge-deck at the companionway. Then mounted the Garmin onto that to starboard (its designed to mount on a horizontal surface). It's all very experimental at this stage, haven't sail tested it (cause doing months of house renno) so haven't put anything online yet. Not sure if unwary crews' feet will bust the fishfinders mount or not (the handheld GPS mounts on the port side of bridge-deck) The other thing it is custom built for my body dimensions (For larger crew it wouldn't work)

What i have also found is the bridge-deck is very useful as a hatchway seat and has semi dry cockpit stowage under it. It's also a step which helps going from cabin floor to cockpit seat level easier. While on land (mast is tarp ridgepole, fairly low) i've removed the cabin inside step and the bridge deck step covers for it, can kneel on it to exit or swing in and sit on it to enter cabin, this opens up cabin space and under cockpit stowage/battery access as well. When using the cockpit Trangia the bridgedeck becomes bench space and can keep unused Trangia parts under it out of the way.

[Watto]

Andrew,

Any details or pics of the transducer mounting through hull?

I was going to mount my one on the transom but figure my kids will use it as a step and break it.

[Andrew]

Ive just mounted my transducer on the transom and hope that works. Other I563s have done this.

Prevoius posts have mentioned that a transducer could be mounted in a glassed in tube or box against the hull. Then filled with silicone or oil and capped. Locations and details vary, anywhere on the hull or keel thats accessible from inside cabin. Suggest PM Peter T for advice if going down this route as he has experience

I'd avoid cutting holes in hull if possible..

I always try simplest methods first, so transom one went on. Its tucked in between the starboard boarding ladder and rudder, a fairly safe spot. The ladder protects it (or a protective cover could be added)

These guys fitted inboard transducers. One guy just stuck it in a blob of silicone against hull. Another made a flat epoxy mix and stuck the transducer into that.

https://www.trailersailerplace.com.au/p ... hp?t=15555

[Ozzie]

Interesting stuff regarding position of internal mounting in that link Andrew. If internal, the front storage compartment I think is just the inside of the hull. At that point is there extra thickness of the developing keel, I can’t recall. If I ever get around to putting mine in I think I’ll use your method. Not really going fast enough to need much forward notice . If the bottom is coming up, slow down.

Anyway it will be interesting to see how you go, thanks for the research so far.

[Andrew]

Thanks Ozzie, if my transom mount doesn't work out, might try silicone blob/PVC tube in forward compartment method, its definitely worth a try.

[Peter T]

This worked for me on my last boat. What I did was to cut a threaded polly pipe end and bogged it and then glassed it to the inside of the boat. Had the transducer in it snugly and filled it up with olive oil to above the transducer and had the cable fit into a slot cut into the screw on cap. Mine was fitted to the centre of the hull front the inside forward from the mast and in front of the keel so there was nothing in its way. It could see straight through the fibreglass of the hull. Worked an absolute treat. Only thing is that this was just a depth sounder which had a round transducer which was meant to be mounted through the hull but I don't like too many holes in my boats. Cheers