Finding himself somehow losing balance, Joseph Leidner reacted by using the flight ability bestowed upon him by his septima to pull himself up the stairs, however making sure his flight path resembled normal gravity close enough to not arouse suspicion.
As the deck came into his view again, he preemptively raised his hands, shouting "I surrender!". He didn't want to endure unnecessary injury.

After he had landed and thus a good view of the deck, Joseph looked for his suitcases, using gravity slingshot to launch them into the closest(to the suitcases) divers that were not paying attention to them.

Additionally, should he find himself losing balance again, Joseph would quickly pull the suitcases towards him, to prevent them from going overboard while he was unable to look.