We sought to evaluate changes in subjective experience and postural performance among older adult passengers during the first 2 days of a sea voyage. On a vacation cruise, volunteer passengers gave verbal ratings of subjective bodily stability and awareness of ship motion followed by performance on the tandem Romberg test while facing fore-aft and athwartship. Data were collected when the ship was at the dock and on each of the first 2 full days at sea. Ship motion reduced subjective bodily stability and performance on the Romberg test and increased awareness of ship motion. On the first day at sea, Romberg performance was more strongly impacted by motion of the ship in roll (i.e., when facing fore-aft) than in pitch (i.e., when facing athwartship). Also on the first day at sea, subjective bodily stability was correlated with Romberg performance when facing fore-aft but not when facing athwart. In summary, at the beginning of the voyage older adult passengers on a sea voyage exhibited consistent changes in subjective awareness and postural performance. Subjective reports were correlated with postural performance in ways that appeared to be functional. We suggest that this finding may help to illuminate the role of conscious awareness within ecological analyses of perception and action.