A device for underwater deployment, the device including: - a buoyant member; - a weighted member; - a tether extending between the buoyant member and the weighted member; - a body positioned on the tether; - a plurality of arms, each arm including: - a primary segment which is hingedly connected to the body; and - one or more further segments which are configured to outwardly extend from the primary segment; wherein, for each arm, a respective petal line connects the primary segment to a connection point on the tether intermediate the body and the buoyant member; such that, when introduced to an underwater environment, the buoyant member and weighted member move apart from one another thereby to tension the tether, characterized in that, each arm is configured to upwardly and outwardly rotate about its respective hinged connection from a storage configuration to an operative configuration; and wherein the tensioning of the tether increases separation between the connection point and the body, thereby to correspondingly tension the petal lines for effecting upward and outward rotation of the arms from the storage configuration to the operative configuration; and wherein, upon rotation of the arms to the operative configuration, the arms lock with respect to the body and a region of the tether intermediate connection point and body remains slack, thereby transferring a downward force applied to the body to the connection point via the petal lines and the primary segments rather than the tether. - a buoyant member; - a weighted member; - a tether extending between the buoyant member and the weighted member; - a body positioned on the tether; - a plurality of arms, each arm including: - a primary segment which is hingedly connected to the body; and - one or more further segments which are configured to outwardly extend from the primary segment; wherein, for each arm, a respective petal line connects the primary segment to a connection point on the tether intermediate the body and the buoyant member; such that, when introduced to an underwater environment, the buoyant member and weighted member move apart from one another thereby to tension the tether, characterized in that, each arm is configured to upwardly and outwardly rotate about its respective hinged connection from a storage configuration to an operative configuration; and wherein the tensioning of the tether increases separation between the connection point and the body, thereby to correspondingly tension the petal lines for effecting upward and outward rotation of the arms from the storage configuration to the operative configuration; and wherein, upon rotation of the arms to the operative configuration, the arms lock with respect to the body and a region of the tether intermediate connection point and body remains slack, thereby transferring a downward force applied to the body to the connection point via the petal lines and the primary segments rather than the tether. - a primary segment which is hingedly connected to the body; and - one or more further segments which are configured to outwardly extend from the primary segment; wherein, for each arm, a respective petal line connects the primary segment to a connection point on the tether intermediate the body and the buoyant member; such that, when introduced to an underwater environment, the buoyant member and weighted member move apart from one another thereby to tension the tether, characterized in that, each arm is configured to upwardly and outwardly rotate about its respective hinged connection from a storage configuration to an operative configuration; and wherein the tensioning of the tether increases separation between the connection point and the body, thereby to correspondingly tension the petal lines for effecting upward and outward rotation of the arms from the storage configuration to the operative configuration; and wherein, upon rotation of the arms to the operative configuration, the arms lock with respect to the body and a region of the tether intermediate connection point and body remains slack, thereby transferring a downward force applied to the body to the connection point via the petal lines and the primary segments rather than the tether.