To be in the same boat as someone means being in the same situation; having the same problem.
If people are in the same boat, they are in the same predicament or trouble.
To be in the same unpleasant situation as other people.
1. A: Bobby, I’m short this month, do you think you can lend me some cash?
B: Sorry, I’m in the same boat.
2. Jenna and Matt have been trying to get out of going on this business trip but now they’re in the same boat.
3. I got so angry when it started to rain but soon realised that we’re all in the same boat.
4. The new college students were in the same boat.
alike, equal, even, on a par, on equal or even terms, on the same or equal footing, together