"When were you on that boat?"
Translation:¿Cuándo estuviste en ese barco?
There is no need for "tú" because "esuviste" is already in the "tú" form.
You could however add it to emphasise that you are specifically asking about "you" (as opposed to someone else).
Because this is a question the "tú" would have to come after the verb...
- ¿Cuándo estuviste tú en ese barco?
Why is 'bote' not accepted? 'Bote de vela' is a sailboat. Translated forward and backward. 'Barco' is a ship. A yacht is something else. To those of us who sail, there is a huge difference. Any spanish speaking sailors out there to comment? Bote=dinghy? Barco significa que?