"Whatever floats your boat".
What does that mean? When can I use it? Is it just about food?

Question

Answer

No, it's not about food. It is very idiomatic and is about preferences or likes.

(1) 'Do whatever floats your boat' = 'Do want YOU want'
(2) A:You want to see a movie or go to a restaurant? B: 'Whatever floats your boat' = 'Whatever YOU prefer'
(3) 'Studying doesn't really float my boat much' = 'I don't really care for studying'

Some more explanations here:
https://www.urbandictionary.com/define.php?term=whatever%20floats%20your%20boat

Answer

Thanks Mr. Chris

Answer

It's means whatever you like or your personal taste. For example:

"You can have chips or mash with your sausage; whatever floats your boat."

And no, it's not just about food. It's for general preference.