float someone's boat    

If something floats your boat, you find it exciting, attractive, or interesting.

I can see its appeal. But it float my boat.

in the same boat

If you say that two or more people are in the same boat, you mean that they are in the same unpleasant or difficult situation.

We are all in the same boat as the miners. People all over Britain are being made redundant every week.

If baldness is creeping up on you, take heart -- 40 per cent of men under 35 are in the same boat.

We were two mums in the same boat and able to make each other feel better.

push the boat out 

If you push the boat out, you spend a lot of money in order to have a very enjoyable time or to celebrate in a lavish way. This expression is used in British English.

I earn enough to push the boat out now and again.

Keep an eye on . He's likely to push the boat out among his friends.

rock the boat

If someone tells you not to rock the boat, they are telling you not to do anything which might cause trouble or upset a stable situation.

While he is careful not to rock the boat Juventus with any ill-timed criticism, there is clearly some frustration that he is not being used to maximum effect.

Diplomats are expecting so much instability in a power struggle after his death that they argue it's unwise to rock the boat now.

If someone is rocking the boat, their behaviour is likely to cause trouble or upset a stable situation. Behaviour like this can be described as boat-rocking.

Before the report was concluded, he pulled back on the subject. I suspect the other parts of the White House complained he was rocking the boat.

I'm outspoken, sometimes critical of the organization, which is seen as boat-rocking, upsetting a comfortable arrangement.