A few questions:

1) For the coffee can I can see no fluids allowed.  I had a student ask about using "Silly Putty".  I would still consider this a fluid as it would form to the shape of its container.  I feel like there can be a blurry line between fluid/solid for some materials.  What are your thoughts on Silly Putty?

2) For the barge event, it says the "bottom surface of barge must fit inside 15 cm x 15 cm".  I had a student build a barge with these dimensions on the bottom, and then the walls beveled outward towards the top of the barge. So that once underwater the barge is more than 15 x 15.  I would like to confirm if this design is OK or not?

Thanks!