Yes you can. If you have gear that fits and you are comfortable with, by all means use it. We only ask that you let us inspect it to ensure that it is SCUBA quality and in good working order. Some fins are designed for snorkeling and lack the features or blade stiffness required for SCUBA diving. If your gear is old and breaks during class, it would be an inconvenience for all students, and now our attention will be focused on the problems that can arise.