That the exact and definite cause of petitioner’s illness is unknown cannot be used to justify grant of disability benefits, absent proof that there is any reasonable connection between work actually performed by petitioner and his illness.   It bears noting that the company-designated physician of respondent who monitored petitioner’s condition and treatment for several months categorically stated that petitioner’s illness is not work-related was controverted by petitioner’s own physician, however. Section 20 (B) of the POEA Standard Contract provides that [I]f a doctor appointed by the seafarer disagrees with the assessment, a third doctor may be agreed jointly between the employer and the seafarer. The third doctor’s decision shall be final and binding on both parties. This procedure however was not availed of by the parties.   While the Court adheres to the principle of liberality in favor of the seafarer in construing the POEA Standard Contract, it cannot allow claims for compensation based on surmises. When the evidence presented then negates compensability, the claim must fail, lest it causes injustice to the employer.30[30]     WHEREFORE, the petition is DENIED.   SO ORDERED. 30[30] Ibid.