Southwest Pass

[Harley123]

Ok guys and gals maybe somebody can help me understand this because it has me puzzled. Went out to the pass and fished caldwell reef fished until about 1100 fish finder would go off telling me fish around the reef every so often ok Well when I got ready to leave the reef I left the fish finder on just curious and watching for deep holes and stuff well I was idling north up the pass back to the landing and the fish finder was going crazy the screen was showing fish everywhere in the deep water of the pass stopped a few times trying to catch what could be there but nothing and all these fish was holding in 25 ft of water what kind of fish is it and why was nobody fishing these deep holes holding fish can they be caught in that deep of water explain please someone