Underwater Booster

FIG. 1 is a front, right perspective view of the underwater booster; FIG. 2 is a rear, left perspective view thereof; FIG. 3 is a bottom, left view perspective thereof, FIG. 4 is a front view thereof; FIG. 5 is a rear view thereof; FIG. 6 is a left view thereof; FIG. 7 is a right view thereof; FIG. 8 is a top view thereof; FIG. 9 is a bottom view thereof; FIG. 10 is a partially enlarged view of FIG. 1 ; and, FIG. 11 is a partially enlarged view of FIG. 3 . In the figures, broken lines depict portions of the underwater booster that form no part of the claimed design. In FIGS. 1 , 3 , 10 and 11 , the dash-dot-dash broken lines encircling portions of the claimed design are illustrated in an enlargement view and form no part of the claimed design.