6/5/2020 E-Library - Information At Your Fingertips: Printer Friendly Significantly, petitioner does not proffer a reason for his failure to undergo a postemployment medical examination within three (3) working days from his return given that he claims he suffered the illness during the term of his employment contract, from July 2001 to April 2002. At the least, petitioner should have reported that he was suffering from symptoms of his illness while on board respondents' vessel during the term of his last employment contract. Contrary to his present claims, on the date nearest the expiration of his employment contract, specifically, 16 April 2002, petitioner accomplished a Debriefing Questionnaire acknowledging that "all [was] ok during his contract[,] including his health."[19] He deliberately glosses over the mandatory nature, of the post-employment medical examination, which he did not undergo, by his general averment that after expiration of his last employment contract in April 2002, he underwent medical examination from June 2002 to April 2003, and was no longer re-deployed since he was found "UNFIT" due to a work-related illness. To our mind, such a claim is neither here nor there, and is clearly far from the requirement that a claimant must establish his entitlement to disability benefits under the law by substantial evidence.[20] We cannot overemphasize that "self-serving and unsubstantiated declarations are insufficient to establish a case x x x where the quantum of evidence required to establish as fact is substantial evidence."[21] Petitioner himself, in paragraph 56 of his petition, highlights the apparent conflict in his medical certifications, which, in any event, was done beyond the three-day period of the seafarer's return or sign-off from the vessel to undergo the mandatory postemployment medical examination: 56. Indeed, the medical certification issued by Dr. Calanoc dated July 23, 2002 declared [petitioner] fit to work. Said certification also stated that he underwent physical therapy for ten (10) sessions. But the said certification was later on supplanted by another certification by Dr. Calanoc which stated that [petitioner] has undergone Consultation/Pre-Post employment Medical Examination from June 11, 2002 but is found to be UNFIT for work with the DIAGNOSIS IMPRESSION: Herniated Disc L3-L4-L4-L5, which is WORK RELATED.[22] (Emphasis supplied) We, thus, cite with favor the Court of Appeals' disquisition, defining the nature of employment of Filipino seafarers and the applicable law therefor: Seafarers are considered contractual employees. Their employment is governed by the contracts they sign every time they are re[-]hired and their employment is terminated when the contract expires. Their employment is contractually fixed for a certain period of time. They fall ¦ under the exception of Article 280 whose employment has been fixed for a specific project or undertaking the completion or termination of which has been determined at the time of engagement of the employee or where the work elibrary.judiciary.gov.ph/thebookshelf/showdocsfriendly/1/60102 12/15