The Bug:
Sculk sensors are not activated upon quick actions in a boat.
Steps to Reproduce:
Place an get inside of a boat.
Tap the fowards key quickly. (W by Default).
Tap the left key quickly. (A by Default).
Tap the right key quickly. (D by Default).
Tap the backwards key quickly. (S by Default). (No backwards movement is actually detected by a sculk sensor whilst inside of a boat. See See MC-210712).
→ ❌ Notice how the sculk sensors does not activate upon doing any of these things, if you do them quickly enough.
Additional Information:
Quote from the 20w49a Changelog, "A vibration is anything that causes physical motion". I would definitely consider all of these as physical motion, as you are physically moving.
Can confirm 🙂