Shot weeks apart, I made two films of personal sightings while on public outings, in the company of the great mammals off Cape Cod. Like icebergs, very little of their bulk, beyond shimmering back and a rearmost dorsal fin is visible as they glide the surface. These forty-ton humpbacks power dive with a grace and purpose that had me conjuring their descending views; diminishing jagged streaks of light into plummeting depths of darkness.