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Author Topic:   Fish Finding
btb posted 04-19-2008 09:11 AM ET (US)   Profile for btb   Send Email to btb  
Forgive a newbie-type question: I have used GPS units for many years but haven't really much used a SONAR and fishfinder. But I think I should use mine more often to really find good fishing spots. What level of increased fish-finding ability does one get with a more expensive fish finder SONAR?

I currently have a low-end Garmin 240 Blue Fishfinder--it was on the boat when I bought it--and my fishing buddy, who is an electronics whiz, says the technology is fairly simple in SONAR and that upgrading to a better unit would provide no additional real information.

So does a better SONAR mean more usable real information when looking for bottom structure and fish? I fish the ocean off La Jolla, California, often in waters around 100-feet deep, sometimes in water 1,500-feet deep. Other than penetrating to greater depth, will a better unit give me increased real information with which to increase my catch?

jimh posted 04-19-2008 09:27 AM ET (US)     Profile for jimh  Send Email to jimh     
[Moved from another discussion.]
jimh posted 04-19-2008 09:35 AM ET (US)     Profile for jimh  Send Email to jimh     
As SONAR units get more expensive, they usually provide:

--a larger display

--a color display

--more powerful transmitters

--more sensitive receivers

--better transducers

All of these factors tend to provide the operator with more information to interpret. The ability to find fish is probably more dependent on the operator's ability to interpret the SONAR display than on the SONAR itself. However, I do notice that people who are fishing for a living tend to use larger, more colorful, more powerful, and more sensitive SONAR units, and they use them in conjunction with more expensive transducers.

As for your electronics wizard friend, I would say that, yes, all SONAR devices operate on the same fundamental principal, but that does not reduce them all to the same level of performance.

One subtlety of fish finding, for example, is that certain species of fish produce stronger acoustic echoes at certain frequencies. This effect is used in commercial SONARs to allow discrimination between species by tuning the frequency of the SONAR.

bigjohn1 posted 04-20-2008 09:20 AM ET (US)     Profile for bigjohn1  Send Email to bigjohn1     
Your buddy is both right and wrong. While sonar technology is fairly simple, there is a significant difference between your current unit and the higher-end units. Your unit would be more than adequate for many types of shallow lake fishing. Out in the ocean though with greater depths to cover, rougher water, and in general, or more punishing environment, the Garmin 240 is not the best choice given current technology.

Here are a few general advantages to the higher-end units and what benefit you can realize by using them:

1. Higher power (wattage). This will help the unit "see" deeper (in a given frequency) and in shallow water, it will provide much better detail.

2. Much better display clarity. Your Garmin unit provides 240x240 pixel resolution. While this is adequate for some applications, units with higher resolution will provide a much better overall screen presentation and will assist you in target recongnition.

3. Better sonar signal processing which, in conjunction with points 1 and 2, give you better overall target discrimination.

4. Larger screen area. The benefit here is fairly self-explanatory.

All of the above mumbo jumbo aside, try going out on a trip with someone who has a high-end unit. If you were to see how a 10" unit with 800 x 480 screen resolution and 600-1000 watts of power operated, you would want to throw the Garmin 240 promptly in the trash can and upgrade.

btb posted 04-24-2008 09:09 AM ET (US)     Profile for btb  Send Email to btb     
Jim, Bigjohn,

thank you for your comments and pointers.

I guess my question was pretty funny, with the Garmin 240 on one end of the scale and a 3 or $4,000 system on the other!

I am not about to spend multiple thousands on a fishfinder, but that said, if there are cost-effective and tangible improvements to be had, then I am game, to some degree.

So what are your thoughts on 1) the degree of improvement I would get and 2) the relative merits of a) the Garmin 400C and b) the Raymarine DS600X??

Would it be worth it to make this step, or are the real benefits only there with the top-end systems bigjohn espouses?

bluewaterpirate posted 04-24-2008 09:53 AM ET (US)     Profile for bluewaterpirate  Send Email to bluewaterpirate     
btb ......

FF technology has changed dramatically over the last three years. When looking the new FF technology I feel you have to look at not only the technology but the functionality and display features. I've always thought that marine electronics should be robust enough to fit your needs but not to the point of complicating using it. Researching and understanding the technology is one thing but seeing it in action is a totally different experience. With that said here are some pictures/video of a Raymarine DS 500/Furuno FCV 620 in action on the water.

I used a Raymarine DS 500 (the smaller cousin of the DS 600) for three years. The unit was very easy to use and had good easy to understand functionalities.

Pictures/videos are worth a thousand words. 15881816/file.jpg 15881819/file.jpg 15881818/file.jpg 33486029/file.jpg 33486033/file.jpg 33486030/file.jpg 15881444/file.jpg

Another ugood unit in the same price range is the Furuno FCV 620. I currently have one installed on my Whaler. I changed over to this unit from the DS 500 not because I was unhappy with the DS 500 but because I got a great deal (free). The unit uses the same technology as the Raymarine units but has knobs to control gain and display functionalities. The FCV 620 is easy to use and has good straight forward functinalities.

Both units have good displays.

Video/pictures 720790#imageID=33486016 33486028/file.jpg 13510239/file.jpg 13510238/file.jpg 13510242/file.jpg 15874863/file.jpg

The DS 600 and FCV 620 are in the same price range and are good values for the money.

There you go.


bluewaterpirate posted 04-24-2008 10:12 AM ET (US)     Profile for bluewaterpirate  Send Email to bluewaterpirate     
Forgot to mention prices. These came from By Owner Electronics (BOE).

Furuno 620 TM ducer ...... $881

Ray DS 600 TM ducer ...... $771

Ray DS 500 TM ducer ...... $501


bigjohn1 posted 04-24-2008 08:03 PM ET (US)     Profile for bigjohn1  Send Email to bigjohn1     
Great points made by Tom. btb, you don't need to spend thousands of dollars to get MUCH better performance than your current Garmin 240.
btb posted 04-25-2008 11:25 AM ET (US)     Profile for btb  Send Email to btb     
Guys, thank you for your help and advice.

Tom - great pictures and video - now I SEE what you guys are talking about! I have never seen anything like that on my screen. Anyone want a 2nd-hand 240???


btb posted 04-25-2008 12:59 PM ET (US)     Profile for btb  Send Email to btb     
Furuno FCV620 ordered from BOE - they must have a sale, 10% less than above price with TM trans...


bluewaterpirate posted 04-25-2008 01:41 PM ET (US)     Profile for bluewaterpirate  Send Email to bluewaterpirate     
Bill ......

Great choice ..... it's real easy to use.


btb posted 05-22-2008 02:12 PM ET (US)     Profile for btb  Send Email to btb     
I am not sure what's going on, but since I installed the Furuno FCV620 fish finder to replace the Garmin 240, there's a heck of a lot more fish in the ocean around here!

The unit seems to perform very well and is reasonably easy to use and navigate around - I have only been out with it once but all indications are that i am heading to a far more informed fishing experience.

Thanks again to all who provided input on this and my NMEA thread.

BTW, while I have two-way communication between the Furuno and the Garmin 276C chartplotter, I was disappointed to discover that Garmin only accept GARMIN PROPRIETARY sounder input. I am miffed at Garmin over this because, for one thing, they say their unit sends & receives NMEA 0183 data - and that it has displayed sounder info in the past: they do however, in the latest version of the 276C manual, imply only Garmin sounders will work. OK, so I guess I have no contractual beef with Garmin, but for them to retreat into proprietary-based communications to me is petty-minded and restrictive, and will drive me away from Garmin as a serious tool provider. The big boys use open systems compatibility - and shame on Garmin for being so restrictive. I guess that's the end of the road for me & Garmin.



jmorgan40 posted 05-25-2008 10:36 PM ET (US)     Profile for jmorgan40  Send Email to jmorgan40     
As mentioned earlier, there is a big difference in units. I have a Garmin 240 Blue installed that came with the boat. I added a Lowrance LCX-26C HD. There is no comparison with the added power of the Lowrance. The Garmin probably marks only 20% of the fish the Lowrance marks.

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