Garmin Depth Finder

[ECR]

Hello
We have an 2017 R25 SC and it’s our first boat so learning every day.

I noticed that when we are underway the Garmin depth finder stops reading the depth and the depth data point blinks. The moment I stop it reads the depth and is fine and stops blinking. I reset to factory settings and that did not work.

Is it normal that it would not read the depth when you are underway? On average we are going between 10-12 NM. The depth finder is set to “auto” as well.

I would certainly appreciate any advice.

Thanks in advance!

 

[Mike and Sarah]

Loosing bottom while at speeds greater than say 5-7 mph is normal. Water flow and bubbles move across the the transducer location causes this. Our 27 outboard was a little better than our new R31. While at speed I just look at the contour lines on the chart plotter page. From your location on the map you get an idea of how deep it is but not perfect.
At Slower speeds the depth registers correctly while fishing, Crabbing and shrimping.

 

[Kim and Ed]

Check the fluid level in the transducer. It is located near the transom on the starboard side in my 2016 R27. I had the same condition and things went back to normal as soon as I topped up the unit. I used RV antifreeze. Check the user manual for refilling info.
Ed/

 

[Chimo]

Hull and speed are definitely factors. Our RT25SC holds well at 12-13 knots down to 5-600 ft most of the time. If I lose the signal and I’m heading into less than 100 ft or there are rocks on the chart I slow to 10 knots and it usually recovers quickly.

There are several posts about checking fluid levels in the transducer. Though I love preventative maintenance,this is one of those things I’ve never done in 5yrs/450 hrs. I figure it’s a “it’s working fine, don’t fix it “ item. Am I missing something ?

 

[kelpline]

The Garmin transducer on our 2011 C28 was located in the starboard stern above the propellor, not good, the sounder pings will not go thru air bubbles. We pulled out the transducer wire and unit, rerouted it to beside the shower sump box outside the head, and epoxy glued it to the hull. We created a little ledge out of regular fiberglass resin and 2/3 of a plastic costco nuts lid, and used the proper epoxy resin for the final glue down of the transducer. The sounder now reads down to 1800 ft. at 10 knots. And at 3 knots we can see indivdual chinooks salmon in 100 feet of water.

 

[BB marine]

The Garmin transducer is a Airmar P79 shoot thru the hull transducer. It requires a clear shot through the hull to work properly. If it is glued in and the adhesive is coming loose it will give erratic readings . If it is a cup style that requires Propylene glycol or a liquid. If the liquid level is low than you will experience the same issues. The folks at Fluid Motion (Ranger-Cutwater) Have a tendency to forget the installation of the sealing o-ring for the cup. After a period of time the level drops and then the transducer starts to act erratic. I checked a fellow Ranger Tug owners transducer Cup last summer starboard compartment aft almost at the transom. This Tug owner said his never worked right. It was a 2016 R25. When I removed the transducer from the cup it was bone dry and there was no o-ring. I poured some water in the cup just to test it, installed the transducer and he was amazed. It has never worked right since we bought the boat!

On the Cutwaters you will not find the transducer installed in the aft section of the boat. The transducer must be installed in the forward section, fore or the hull step. If the transducer is installed behind the step there will be a lot of interference from disturbed water caused from the step.
https://www.google.com/url?sa=t&rct=j&q ... GaU8RFhBZC

 

[bob daily]

As per the Garmin / Airman transducer selection guide, the Airman-P79 in hull transducer is not for cored hulls and the max fiberglass thickness should not exceed 5/8 inch. Also the placement of the transducer is critical for proper operations. Will it work if not installed as per the manufacturer recommendations, yes but it will not perform at 100% does Fluid Motion use cored hulls on the Ranger and Cuttwater boats? My 2009 R-21 EC has a cored hull and the fiberglass was thicker than 5/8 inch where the transducer was mounted from the factory. The Garmin depth sounder / fish finder is only as good as the transducer, so the weak link in the system seems to be the transducer! There have been more posts on this site about poor depth readings due to the transducer than any other subject!
The depth sounder is a critical piece of equipment for us shallow water sailors and should be working properly for safe travels. Stay safe! Bob

 

[praymond]

We have a 2016 Ranger Tug 27 and the Garmin needs RV Antifreeze often. I even purchased the O ring but it still seems to leak. When I just top off the fluid the depth finder works fine. Just can't figure out how to keep it from losing RV fluid.....

 

[HookedUp]

My Albemarle 28' had an in hull transducer. It lost bottom at planing speed and I relocated it due to leaking. My Robalo had a transom transducer and it too lost bottom at planing speed. My Sailfish has a thru hull transducer and it reads great at all speeds.

Doubt I'd ever buy another boat without a thru hull. Have water temp, excellent views and the ability to see down at high speeds. Since I fish a fair amount being able to see bait balls and fish at high speed is important. And, locating temperature shifts is critical for some fish.

 

[gwishon]

I’ve found that lubricating the O ring well with Vaseline helps. Once I did that, the leaking completely stopped.

 

[S. Todd]

We had a 2015 R25SC for 6 years. We had two issues with our depth finder. In the beginning of the 2nd year it failed to read depths because it lost its antifreeze in the cup. Replaced the antifreeze with -100 and it worked fine forever (we had the o-ring properly carefully seated when we reinstalled). It worked at every speed from 0 to 20 miles per hour and nominal depths all the way up to 600 feet. The only other issue we had was when it mysteriously turned off the transducer. Once I figured out how to turn it back on, it again worked flawlessly.

 

[bob daily]

IAW the transducer selection guide the Airman P-79 should read depth of 800 to 1200 ft depend on the frequency selected. If it's only reading 600 ft I would say your not getting the full capacity of your unit. Bob

 

[snydzy]

I’ve found that lubricating the O ring well with Vaseline helps. Once I did that, the leaking completely stopped.

You do not want to use Vaseline on your o-rings. The petroleum-based jelly eats away the rubber, causing the rubber to stretch, or tear sooner than normal. The preferred o-ring lube is a Teflon or Silicone base to keep the rubber soft and supple.

 

[Chimo]

IAW the transducer selection guide the Airman P-79 should read depth of 800 to 1200 ft depend on the frequency selected. If it's only reading 600 ft I would say your not getting the full capacity of your unit. Bob

I can get 900 ft, even 1000 ft in calm waters and hull speed but at 12 kts I often loose bottom at 5-600 ft. I'm happy with that. I'm not fishing at that speed and I'm not likely to run aground. I keep an eye on the chart for depths. I think it makes a big difference whether you select frequency manually or leave it on auto as I do.

 

[FlyMeAway]

I’ve found that lubricating the O ring well with Vaseline helps. Once I did that, the leaking completely stopped.

You do not want to use Vaseline on your o-rings. The petroleum-based jelly eats away the rubber, causing the rubber to stretch, or tear sooner than normal. The preferred o-ring lube is a Teflon or Silicone base to keep the rubber soft and supple.

More specifically, use this: https://www.super-lube.com/o-ring-silicone-grease

You can also use the general-purpose Superlube (synthetic or silicone), if you don't want to buy the o-ring specific stuff. I haven't found a difference between the two over more than a decade of marine use.