The ornamental design for a submarinetubtoyholder, as shown and described.
FIG. 1 is a perspective view of one embodiment of a submarine tub toy holder.
FIG. 2 is a front view of the submarine tub toy holder illustrated in FIG. 1.
FIG. 3 is a back view of the submarine tub toy holder illustrated in FIG. 1.
FIG. 4 is a top view of the submarine tub toy holder illustrated in FIG. 1.
FIG. 5 is a bottom view of the submarine tub toy holder illustrated in FIG. 1.
FIG. 6 is a right side view of the submarine tub toy holder illustrated in FIG. 1; and,
FIG. 7 is a left side view of the submarine tub toy holder illustrated in FIG. 1.
The broken-line disclosure in the views is understood to represent portions of the article in which the claimed design is embodied, but which form no part of the claimed design.