Employment Contract ' the only qualification prescribed for the physician entrusted with the task of assessing the seaman's disability is that he be company-designated.[26]   cralawDr. Pidlaoan examined and treated petitioner from the time he was repatriated up to his recovery and subsequent assessment as fit for duty on December 13, 2000. As in theGerman Marine case, the extensive medical attention extended by Dr. Pidlaoan enabled the latter to acquire familiarity, if not detailed knowledge, of petitioner's medical condition. No doubt such specialized knowledge enabled Dr. Pidlaoan to arrive at a much more accurate appraisal of petitioner's condition, as compared to another physician not privy to petitioner's case from the very beginning. [27] Indeed, the assessment of the three other personal doctors of petitioner could not have been that reliable considering that they based their conclusions on the prior findings of Dr. Pidlaoan; moreover, they examined petitioner 7 or 8 months after he was assessed as fit to work and treated him for only one day.     The only requirement stated in the POEA Standard Employment Contract, as explained in the German Marine case, is that the doctor be companydesignated, and no other. Though it is prudent and advisable to have a doctor specialized in his field to examine the seafarer's condition ordegree of illness, the contractual provisions of the parties only require that the doctor be 'company-designated. When the language of the contract is explicit, as in the case at bar, leaving no doubt as to the intention of the drafters thereof, the courts may not read into it any other intention that would contradict its plain import.[28]   cralaw Furthermore and most importantly, petitioner did not question the competency of Dr. Pidlaoan and his assessment when the latter declared him as fit for duty or fit to work.   cralawAdditionally, petitioner, instead of questioning the assessment of the company-designated doctor, executed a release and quitclaim in favor ofrespondents, around three months after the assessment. In executing the said document, petitioner thus impliedly admitted the correctness of the assessment of the company-designated physician, and acknowledged that he could no longer claim for disability benefits.