Uw melee training

Deep inside underwater Tiger Sharks training camp, two fighters meet in a training chamber for some melee battle - Team leader Arlena, and deadly shark Theresa. Both wearing their breathing apparatuses, as the water's treated to have no oxygen for Theresa to use. Even encumbered with diving gear, both are deadly fighters and force to be reckoned with.

Which of them shall emerge victorious :3 ?