Here is very nice animation. Why is getting the real thing so impossible? If we can visit the Marianas Trench why can’t we wire up a whale?
I suspect that attaching a camera to a sperm whale would contravene the Marine Mammal Protection Act. https://en.wikipedia.org/wiki/Marine_Mammal_Protection_Act_of_1972
I’m not sure whether following a sperm whale in a sub would be considered harassment. I’m also not sure whether it would be plausible for any length of time.
I see from Wikipedia that modern subs have a test depth of 1600 feet. Colossal squids inhabit the 3300- 7200 foot range.
We have plenty of remotely operated vehicles that go down that far but I suspect none of them have the stamina to follow a whale for long enough to catch it feeding on a giant squid. And how often do whales actually eat giant squids? You might be chasing a whale for a month or more until it actually eats one.
Attaching “crittercams” to whales has been done. One of the leading giant squid specialists, Clyde Roper, did try hunting the critters with a crittercam attached to a sperm whale but didn’t have any luck.
It also tends to be a bit dark down there and attaching floodlights to the whale is going to tend to be a bit counter-productive.
It would be cheaper to film the whole thing on a sound stage in Arizona.
In addition to the problems already mentioned, visibility is very poor at those depths. If you look at photos of, say, the Titanic wreck, it’s only possible to light a small area. Getting a shot would be a nightmare, as would any attempt to track the whales.
An ROV would be unsuitable, as they are tethered to a host ship.
Or the speed. Deep exploration submersibles are not built for speed; they’re creeping things.
A sperm whale’s speed is harder to pin down with web searches – various sites assert 27 mph, 25 mph, 23 mph, and “no faster than 6 mph.” All of those speeds are much faster than Alvin, however.