Whatever rocks/ floats your boat

[nyota]

Can I use 'rocks' and 'floats' interchangeably in the phrase: 'Whatever ....... your boat'?

I thought I could but it turns out I might be wrong. Is 'rocks' used in the negative context, meaning something bad, after all it's not too good when your boat is rocking, and 'floats' is the positive one used to mean 'whatever works for you'?

[BobK]

I've never met 'Whatever rocks your boat' (meaning 'Do whatever you like'. The idea of negative implications comes from the phrase 'rock the boat' - which means 'make life difficult for everyone else. Example: 'I didn't want to rock the boat, so I didn't say anything'.

b

[Ouisch]

"Whatever _______s your __________" is an expression that means "whatever makes you happy". To "rock the boat" means to upset the situation or cause trouble. So you could say "whatever rocks your world" and mean "whatever pleases you", but not "whatever rocks your boat." Happiness/serenity in the nautical world means a boat floating peacefully on calm water, not rocking.