Dilli: Don't want to rain on your parade, but I believe the museum for the Mary Rose itself is being rebuilt and isn't open to the public at the moment. Might be worth checking if that's all you want to see. Have a look at
http://www.maryrose.org/new_museum/index.html
I might have got it wrong, of course.
Have a great time anyway, whatever you get up to.
If you like beaches, try West Wittering.