There is a good chance that this individual is a 'flu whale' - a hybrid of Blue and Fin

Not to be confused with whale flu

https://pubmed.ncbi.nlm.nih.gov/32170708/

Just when I thought it was safe to go back in the water. Thanks for the extra worries.

What if it was born with a disability?

Should it be called a “Flue” (Fin + Blue) whale?

https://whale-tales.org/flue-the-hybrid-whale-23-7-20/

This has been discussed several times in the past most comments look to be here https://news.ycombinator.com/item?id=11185764

We can't even find a whale that regularly gives itself away with a specific note? Yeah, good luck finding the wreck of Flight 370.

These are very different challenges. Them being in the ocean is almost the only common thing between them. The whale (or whales) is in one piece, near the surface but moving about.

The airplane is either in a few pieces or a debris field, sunk to the bottom and very inert.

Finding one you need a sensor network which can track it in near realtime as you hunt it down. Finding the other you need to map huge swathes of the deep ocean with high enough resolution to be able to see debris.

One is not a "harder version" of the other, but entirely different challenges. It is a bit like saying "oh you can't even make a jetpack? Good luck making a fully reusable orbital launcher." Yeah they are both rockets(ocean) things but they have nothing else in common.

"Our ultra-secretive, stealthy submarine is perfect in all aspects except for the fact that it emits a 52 hertz sound wave." "Give me a sec boss, I'll solve that... 'The 52-hertz whale, colloquially referred to as 52 Blue,...'"

We should manufacture a bot for the lonely whale. A nuclear powered ai based sex doll submarine. Train on other whales behaviors and use 52 hz audio modulation. It could even have a 3D print manufacturing capabilities to bear an offspring.