A tank retaining device for inhibiting a scuba tank from slipping downwardly in reference to a buoyancy control device. The tank retaining device includes a ring member having a diameter smaller than a scuba tank designed for abutting a bottom the of the scuba tank, and a plurality of strap members operationally coupled to the ring member, each one of the plurality of strap members is couplable to a tank securing strap of a buoyancy control device operationally coupled to the ring member.