Transducer decision

[combackid]

I just bought half of my buddy's '31, and it needs a bit of electronics which is part of my buy-in. I think we're going with Garmin units, but I just can’t seem to get anyone who can give me advice on which Transducer to use. The boat is in the Bahamas, goes in November 1 and comes out in June, so the fairing on the bottom isn't the end of the world, but I'd rather not take a chance if I don't have to. In our area, there isn't exactly a great yard, so I am reluctant to have someone cut a big hole and glass around it for fear that the craftsmanship may not hold up over time.

I've heard about this dual frequency stuff being the way to go, but I can't tell if the Garmin GSD22 can even take advantage of it, or if I am just overanalyzing the whole thing. We do a fair amount of Bottom and Tuna fishing and are not pro's, but would like to be some day, so I would like to install something with growth potential.

Any advice for what would be a good application?

Thanks,

Mark

[In Memory Walter K]

A discussion with the Airmar tech guys might be in order once you decide what instruments you are considering. I have found them very helpful. If there are no holes in your hull (old transducer being replaced) you may also want to consider installing one inside the hull since it is solid glass with no coring. It is something fairly easy to do yourself and the loss of signal is surprisingly very small. No fairing block problems and most are adjustable angle units made for deep V applications.

[tunawish]

I have the Garmin with the older version GSD21 and it accepts the airmar dual frequency unit ..

Do what Walter says and give them a call to be sure..

[Harry Woods]

Mark,
The Airmar P79 is an in-hull 50/200 transducer with an adjustable base for hulls up to 22 degrees. It costs about $100 and is easy to mount just forward of the engines. If you order it you must specify you need the Garmin cable. The GSD 22 is the digital module that packs plenty of power.
Harry

[Kevin]

The GSD21 is analog and costs less than half of the GSD22 which is digital. The picture is more detailed with the digital but unless you are making a living fishing or just plain hard core about it the analog GSD21 is fine. I have the 50/200 shoot thru the hull ducer on my 28 and it reads fine all the way to WOT speed but working out some other bugs with it right now. I bought mine for about 79 dollars on ebay. On the work boat I have the GSD22 with a much bigger screen and it reads the bottom densities ie. hard/soft with more detail. The GSD21 can be found for ball park price of 200-250. Less if you buy a refurbed unit. Hope this helps but I am a newbie with this stuff too.

[combackid]

Thanks a bunch fellas! I am going to give Airmar a call and pick their brains, but thanks to all for your thoughts.

Do you have to select which frequency (50/200) you use at any given time or do the machines just figure it out and post the results?

Thanks again guys.

M.

[In Memory Walter K]

I'm not sure how it works with the new digitals, but most of the depth recorders I've owned give you the ability to choose which frequency you want to operate in manually. Most also allow you to choose "both" and you get them side by side on the screen.

[Harry Woods]

Mark,
Garmin advised that the GSD 21 is not compatible with all Garmin units. If I remember correctly, you need the GSD 22 for 4000 and 5000 series GPSMAP units. Also check with garmin before you buy.
Harry