A flotation device for a wellbore tubular has a flotation disk having a tapered exterior profile. A maximum external diameter of the flotation disk is such to enable free longitudinal movement within the wellbore tubular. A plurality of locking segments each has a tapered interior profile cooperatively engageable with the tapered exterior profile. Each locking segment has gripping elements on an exterior surface thereof to engage an inner wall of the wellbore tubular. The tapered exterior profile and the tapered interior profile cooperate to expand a diameter of the locking segments as profile engagement increases.