Last week while doing Unit 1 he learned about ocean currents and whale blubber.
Later in afternoon (the same day we learned about the ocean currents), he was playing in the kiddie pool while it was being filled with the garden hose. He came running up to me shouting, I found a current! He had set a toy boat in front of where the hose was (under water) and observed the boat float away in the current of water from the hose. He did it again this week when he and my dd created a "whirlpool" in the pool by walking in circles and watching their toy boats go around & around in the current.
That same evening as the whirlpool, the water was also a bit chilly. My ds asked if I could bring out the "blubber" (vegetable shortening) so they could put it on their bodies to stay warm in the cold water like the whales do in the ocean.

Thanks, Carrie, for such fun science activities my ds remembers!!!