Skyhawk 172/Cutlass 172
Flight Crew Instrument; Flight Crew Private
Flight Crew Last 90 Days 70; Flight Crew Total 160; Flight Crew Type 160
Conflict NMAC
Flight Crew Took Evasive Action
Human Factors
Maneuvering at 1700' at the beach practice area SE of PNS / NUN; Pensacola approach controller issued a traffic alert 1nm to the north of my position at 1700'. I replied with 'Negativate contact call sign' and nothing else was mentioned. I climbed from 1700' to 2100'; Traffic was spotted at my 11:30 no more than 100' above (Likely at 2200'). Controller was prompted with the near miss and claimed I hadn't reply to her traffic advisory.  The other aircraft was a PA-28 and they didn't have us in sight. Classic high wing cessna below and low wing piper above; and a lack of the controller's input regarding both aircraft's decision to climb in order to avoid each other.
C172 pilot reports a near miss southeast of PNS while talking to TRACON.  C172 pilot; while looking for traffic; climbs to 2100 FT to avoid the PA28 traffic Controller advised was at 1700 FT.  Aircraft miss each other by an estimated 100 FT.