(LEAD) Navy deploys Wildcat choppers amid N. Korea submarine threats
(ATTN: REWRITES throughout, ADDS drill details, navy official's comments in the first 9 paras) By Choi Kyong-ae ABOARD ROKS DOKDO, Feb. 1 (Yonhap) -- Two 'Wildcat' maritime helicopters stood ready to take off from the deck of the amphibious landing s