Help choosing sonar?

[erikpn]

I'm looking for a sonar/fishfinder and finding it extremely hard to find any quality information to make an informed decision. Everything is vague sales pitches when I try google. The rare reviews and suggestions I see in searches are things like "Buy a lowrance. My grandpa had one and it's great" "Buy a furuno." Without anybody stating why and what the difference is between it and other brands with similar specs.

So I have a lot of questions.
How many watts will penetrate how much green coastal water? What determines sonar clarity? What differences are there between the 200kz and 60kz beams, what will it mean for me? All I know is that the 200kz beam is more focused and shows more detail, and the 60kz beam shows a wider area. What can you do with color that you can't do with the different shades of gray?

I'd prefer to be told where I can learn such things about sonar rather than what to buy.

 

[Boatist]

Re: Help choosing sonar?

You would get a better responce in the electronics sections.

Your going about finding a unit the right way and it is very hard to find the right unit for you. At the bottom I will post several Tutorials from Lowrance that are very good.
A Lot depends on how you fish.
For deep salt water you want a unit with lots of power and a narrow cone angle transducer.
When comparing units important to understand power.
Companies give you two types of power, RMS or Peak to Peak.
RMS times 8 will give you the PEP power, 500 watts RMS equals 4000 watts PeP.
1000 Watts RMS = 8000 Watts PeP, 375 Watts RMS = 3000 Watts PeP.

In deep Saltwater Power and resolution are very important.
In shallow water Power and Resolution are not that important.

In deep salt water fishing the bottom then you want a narrow cone angle.
My depth finder has 375 watts RMS and is 192 KHZ to a 20 degree transducer. I can see bottom fish down to about 250 Feet. It will be less depth when have storm and lots of air in the water.
Same power with a 192 khz 8 degree transducer I can see bottom fish out to 600 feet because the narrow cone angle concentrates the power in a smaller area.
The narrow cone angle also let you see more fish in a rocky area or a sloped bottom because of the dead zone.
Fishing sallow water with a flat bottom then you want a wider cone angle. I post a little on dead zone from a site. After that I post some links to tutorials.


http://vexilar.com/pages/support/support_tips/article_006.html

http://www.lowrance.com/en/Support/Tips-and-Tutorials/Sonar-Tutorial/

http://www.lowrance.com/en/Support/Tips-and-Tutorials/GPS-Tutorial/

http://www.lowrance.com/en/Support/Tips-and-Tutorials/Transducer-Guide/