With a very busy and curious toddler, It's challenging to keep him contained. He is busy busy busy and has to be into everything. We recently gave him a little freedom after we baby proofed our cabinets...
he likes to explore window locks, pots and pans, spoons and water.. so when I cook meals, he will ask for water (Bah Bah). I'll give him a baking pan with spoons and measuring cups... he LOVES it. It'll keep him busy for 20-30 minutes.
somedays, I'll add other containers and soups spoons and he will transfer water from one container to another... He also likes ice cubes for fun!
and yes.. he will dunk his head in to blow bubbles. He's been doing this since he learned how to hold his breath in swim school!