Switching to a new tact.

I keep seeing in print, and hearing, people talk of “switching to a new tact”. Sometimes they even are discussing a storm or wind or a boat or whatnot.

This is wrong, right? They mean “tack”, I assume. But it’s so prevalent it’s almost the more frequently used term. Is this just a coincidence and they don’t meant “tack”, they really mean “tact”? And if so, what does that mean? Is it short for “tactic”? Is it not but people mistakenly think it is?

It seems odd if it’s an error that it would be so frequent, because wouldn’t people look it up to make sure? If they mean the sailing metaphor but aren’t familiar with it as such, I’d expect they wonder what the heck it means and check.

And these aren’t off-the-cuff remarks. It’s in situations where people prepare (such as TV scripts, or editorials).