This is a quick summary of the sinking by Sal Mercogliano:

Yeah, probably had a whale of a headache later.

Is "sunk" correct in US English? In UK English the simple past tense is "sank".

PeroK said:

Is "sunk" correct in US English? In UK English the simple past tense is "sank".

Google says this:

Google said:

Use sank as the simple past tense (e.g., "The ship sank") and sunk as the past participle (e.g., "The ship has sunk"). While dictionaries note that using sunk for the simple past tense occurs in informal speech, sticking to sank is the standard rule.

And I use "sunk" as a verb, like "the whale sunk the boat".

berkeman said:

And I use "sunk" as a verb, like "the whale sunk the boat".

What about "sung a song" or "rung a bell"?

Those sound even worse to me.