Saturday, August 18, 2012

Diel, or no diel?

Is this a big diel, or not? This is the question of the day. What we know is the image was captured in the Gulf of Mexico approximately 150 miles due west of Sarasota Fl. The boat was just on the edge of the continental shelf.

The screen shot was taken in the morning (late February) using a Garmin GSD 26 running on low chirp (sweeping 28kHZ to 60kHz) outputting 3000 watts. The transducer is an Airmar 599LH 25 element in hull unit. You can see the depth. There is a fuzzy broad line at 500'. This is most likely a secondary bottom echo. The line below it, running slightly downhill is our puzzle. The line is about 30' thick. and you are seeing about 11.2 minutes of recorded bottom. The descent rate of the line is 5.3' per minute.