Need Advice on New Chartplotter & Transducer

I have searched and not found any recent discussions on these devices. I have a 1990 22' Grady White that is currently equipped with a 2005 vintage Garmin GPSMAP 5212 unit with a thru-hull transducer and NMEA 2000 hub. I use the 5212 for finding fish (not so great) and engine/fuel data. The boat is also equipped with a smaller Garmin GPSMAP 546s unit that I typically use for navigation only while I'm looking for fish marks on the 5212. The boat is powered by a 2005 Yamaha 225 4-stroke which I use for trolling, with socks when needed.

I cannot see perch on this unit and based on what I have read online, the technology of my 2005 equipment is not capable of showing enough definition. I am in the market for a new chartplotter and transducer, and possibly a new NMEA 2000 unit as well - not sure I will be able to use the existing one.

I fish for perch and walleye, so I don't need all the fancy features like side scan and live view, and I don't want to spend the money on this stuff either. I just want to be able to see marks while underway and then see better definition on the bottom for perch. I would like to keep the 546s connected to the current thru-hull transducer for navigation (and as a backup) if possible, but I am not married to this plan.

I would like advice on which chartplotter/transducer to purchase for just down scan or total scan (I think that is all I need) to find marks at speed and then have better definition while trolling or sitting. I assume a transom mounted transducer will be best, but I am not sure. I will replace the thru-hull transducer if that is the better way to go. Also, do I need to replace the NMEA 2000 hub as well?

Sorry for so many questions, but I am not a techie. Thank you to anyone that can point me in the right direction.

Ted 33,

Welcome to the confusing world of modern sonar and navigation electronics. Since your Garmin units appear to be at least 15-20 years old, compared to contemporary units (say within the last 5 years) they are near "dinosaurs". If you want to upgrade, you need to consider things such as the cable connecting type (number of pins and design), thru hull hole size and type (some newer models of sonar have different thru hull mounting designs), and whether a newer unit requires a separate "black box".

Also, when you say looking for fish at speed, what speed? Some transducers are better at returning clearer marks at higher speed than others. In Lake Erie, especially in the Western Basin, having the ability to see out to the side of the boat is important, because in the shallower water fish tend to scatter away from a boat, especially at higher speeds. As for an in hull or transom mount transducer, it depends on your boat. You have an outboard motor, so a transom mount should would work as well as a thru hull (which you already have). Check with the boat manufacturer as to which type transducer they recommend for your boat.

Sonar and navigation units have come a long way in 15 years. Yes, the "target separation" (being able to pick out / separate fish from other sonar returns) is much better in the modern units. However, you need to truly understand how to use any fish finder in order to get the most out of it.

Another option you have is to get a unit and use a pole mount transducer for perch fishing. Once you anchor, you can deploy the pole transducer to scan for perch schools.

I would give more advice, but I'm not familiar with your particular units. I am in the process of replacing an old Lowrance Eagle unit that is at least 20 years old. Finding information on it so far has been mostly unsuccessful. I would contact Garmin and ask them, but be prepared for this to take several communications and a few weeks to get all the info they may have. It took me a long time to research and get all the information I needed from Garmin for my new Garmin Livescope unit, including the mobile system I am building.

Good luck, and stay on them. Eventually you should be able to find a Garmin tech that can answer your questions.

You might also try contacting a Garmin rep, or an outfit such as Boat Things in Columbus that specializes in installing sonar and navigation equipment on boats. There is a lack of both of these around the Port Clinton / Sandusky area.

Boat Things (click it) - Boat Things

West Basin,

Thank you very much for all the thoughts and information. You pretty much confirmed what I suspected was going to be necessary... I need to basically start from scratch due to the age of my current equipment.

When I said I wanted to see marks at speed, I meant while cruising along around 20 - 30 mph. Captain Juls seems to be able to spot marks while she is under way. I would like to be able to at least identify marks without slowing way down. Basically I don't want to be passing over fish and not realize it.

I'm sure I can mount a transducer on the transom, but I would rather have the more protected thru-hull type, if I can get good functionality without spending a fortune.

I will check out the link you provided and probably pay a visit to those guys in Columbus. I've read so much about the big three, being Garmin, Humminbird and Lowrance but I don't know which direction to go yet. I'm sure it's like asking for advice buying tires... many different opinions out there. In the end they are all so much better than what I have now that I'm sure I will be happy with whatever I decide to purchase.

Thank you again for taking the time to provide such an informative reply.

Ted

Marking at speed will depend a lot on your hull. I had a Garmin 741 on the boat that was losing power. It wasn't the wiring and I could never mark fish at speed with that unit so I upgraded to a Raymarine that had the 3D scanning thing. Thought that would be useful for trolling, but it wasn't as life changing as I had hoped. Anyway, with the Raymarine I have essentially a 2023 vintage transducer and I still can't mark fish at speed. I have a Key West with a stepped hull and it just throws off to much turbulance for a transom mounted transducer. Not sure if going to a thru hull would help, but just be aware that hull design will affect you ability to do that.

rkfet, thank you for the heads up on hull design. The Grady White 228 Seafarer doesn't have a stepped hull, so I shouldn't have that issue. But I will certainly verify this before I purchase a new chartplotter and transducer outfit.