Big stripers will consistently be found in 64 degree water if they can find it and still find a way to feed in close proximity. So trophy stripers will be at or near the thermocline (60-90 feet) in summer. They feed at night when boating and recreational activity is less and feeding opportunities are enhanced for the very proficient nocturnal predator. They exert only as much energy as needed to catch a 1 pound carp or gizzard shad every other day. The number of trophy size fish is small compared to the great numbers of school-size stripers.
If you really want to go trophy fishing, troll with down riggers at 60-90 feet or fish with bait (whole anchovies) all night long. Spend a lot of time graphing and isolate individual targets and try to fish for that one fish. Perhaps the very best time to catch a trophy is first morning light just before the sun comes up. Big fish seem most active for the magic 45 minutes of predawn light.
Chances of catching the bigger fish are enhanced in winter when cooling temperature allows the big fish to use the entire water column to forage BUT, they still prefer to feed at night.
The only daytime opportunity for big fish comes Mid April to June 15 when spawning draws them to the top and decreases inhibitions. Dreary days in the dead of winter have also produced trophy sized fish.
Forage conditions have changed enough to make 3-5 pound stripers common in 2012. Another strong shad year in 2012 will allow many stripers to exceed 5 pounds. Unfortunately, like salmon after a spawn, a 5-pound striper is doomed the next year if it can't find enough food to support his larger body mass and greater metabolic needs. Hopefully shad will continue to provide adequate forage and support the larger size stripers now occurring in Powell.
Once a striper tops 10 pounds his mouth is big enough to consume the next size larger forage (carp and juvenile gizzard shad) and it can get as big as he wants to be.