I made a four passes under the Cedar Key fishing pier using a Humminbird 997c SI and a towfish. Looks like there are plenty of things under there to snag a hook on or a fish from. Here are screen shots (using the Yellowfin viewer) of the recordings from the runs. Shallow saltwater, speed 3mph, chart speed 4 and default settings for everything else ...
(http://limbatus.net/info/CKPTF-20110322/tm/picture-003.jpg) (http://limbatus.net/info/CKPTF-20110322/xl/picture-003.jpg) . . . (http://limbatus.net/info/CKPTF-20110322/tm/picture-005.jpg) (http://limbatus.net/info/CKPTF-20110322/xl/picture-005.jpg)
(http://limbatus.net/info/CKPTF-20110322/tm/picture-002.jpg) (http://limbatus.net/info/CKPTF-20110322/xl/picture-002.jpg) . . . (http://limbatus.net/info/CKPTF-20110322/tm/picture-004.jpg) (http://limbatus.net/info/CKPTF-20110322/xl/picture-004.jpg)
There are a few details here => (http://limbatus.net/info/CKPTF-20110322/vptm.gif) (http://limbatus.net/info/CKPTF-20110322/rpttm.html)
Tight lines,
Darrell