The generals visited Internal Security Operations Command Area 4 at Fort Sirindhorn in Tambon Khao Toom, in Yarang district, at 9.45am.
Chalermchai retires at the end of this month and will be replaced by Apirat.
The two were received by Fourth Army Area commander Lt¬-General Piyawat Nakwanit and representatives from Provincial Police Bureau 9, the Southern Border Provinces Administrative Centre and commanders of task forces in the three southern border provinces.
They were briefed on progress in the operations of all agencies in their efforts to restore peace in the deep South.