Sounds like you have a new water garden for your yard. I suggest lily pads and koi.

A freestanding tub? How about adding a tempered glass shelf at the height of the tub and adding some pretty glass bottles with bath salts, bubble bath, etc? They'll be pretty sitting in the light of the window.

it would help if you actually posted pictures. But really, other than covering the lower portion of the window, what else is there? Privately sell your tub, hope to recoup some of the money, and buy a different one.

If this is a shower surround, there's really no logical help to be offered.

If this is a soaking tub, if space permits, there might be a chance that a window well could be incorporated into the design.