What is the fastest way to swim in the sea?

This has been bugging me ever since the wetsuit update for ACNH came out. I’ve always thought the fastest way to swim was by mashing the A button repeatedly so that your character does that arm movement thing over and over, but I also found out that by holding the A button, your character can just calmly kick their legs and swim faster that way too.

I tested this out, and I’m pretty positive that mashing the A button makes you go faster, but my mind could just be playing tricks on me. So with that being said, do I go faster by repeatedly pressing the A button? Or am I better off just holding A?