There were a number of related questions on this, so I pulled together some images and videos about sea life. I went from the shore (tide pools, sandy beaches, further offshore, all the way to the deepest parts of the ocean bottom.

• Tide pools. These have mostly invertebrates in them: sea anemones, starfish, chitons, crabs, green algae, and mussels.
• Some invertebrates in tide pools
• Rock pool spotter. What to look for
• Beach animals
• Flat fish. You can sometimes see these just off sandy beaches. An interesting evolutionary story here.
• The color of sea life depends on how deep the are found.
• Twilight zone
• Hydrothermal vents diagram
• Hydrothermal vent video
• Unexpected life under the antarctic ice
• Ocean depths. Diving deeper and deeper.

I saw this at the 2016 Bay Area Maker Faire, and it was an obvious success with the younger crowd. Since I started doing a monthly 'Science Saturday' at the Santa Fe Children's Museum, which caters to young children, it was an obvious thing to do. Full credit goes to AirRocketWorks for the inspiration and their standard template. Here is my slightly modified template.

On the right I have

1. A bicycle pump with a pressure gauge
2. I 2-liter bottle serves as a compressed air tank
3. The big red launch button
4. The launch tube
5. I keep one template taped to a board
6. This one has hit the ceiling too often
7. On the next picture: construction tubes

The rockets are made from a single standard sheet of paper, with the parts and instructions printed on them. All you need is scissors and masking tape. The rocket tube is wrapped around the construction tube, and the fins and nosecone are cut out and taped on. When the rocket is finished, it is slipped off the construction tube and onto the launcher.

On the construction tubes, I put a strip of tape down the length. This way, if the rocket is made really tight, it may be hard to get off the construction tube, but will fit a bit looser on the launch tube.

At the Children's Museum, there also are colored feathers, ribbons and the like to decorate the rockets. [and for reference, in 2+ hours, 23 rockets were made.]

Since we had talked about global warming earlier, as well as sea life, I did an hour on ocean acidification. In order to introduce the concepts of acids and bases, I brought enough stuff to do the red cabbage acidity indicator demo.

By the way, I had brought this image to illustrate the pH scale, since it showed the colors of the cabbage juice. After a while I realized that this picture dated back to the the days of acid rain. The acid rain problem echoed, on a smaller scale, the ocean acidification problem: fossil fuel burning causing sulfuric acid to rain down and kill lakes, streams and forests. The area affected was not global, though it spanned the US Northeast and Canada, as well as Scandinavia. The solution was regulation to scrub sulfur compounds from smokestacks. This happened after much opposition from the polluters, and now few people remember the days of dead lakes, streams and forests. The other nice thing about this problem was that solution worked fast: it takes only a few rainstorms to clean the air of sulphur compounds, and the ecosystems recovered in a few decades. No such luck with CO2 pollution: CO2 stays in the air for many centuries, and the oceans will take millennia to recover.

Bring: Red cabbage Cutting board and knife Water kettle, water bottle Blender Sieve, spoon 3 or more glasses Lemon juice, ammonia, soda ...

• https://www.thoughtco.com/making-red-cabbage-ph-indicator-603650
• https://critical-angle.net/2017/07/02/may-2017-global-temperature-update-belated/
• annualmay17.png
• co2_916_400_large.jpg
• https://www.pmel.noaa.gov/co2/story/What+is+Ocean+Acidification%3F
• pteropodpics1_med.jpg
• http://slideplayer.com/slide/7946383/
• co2_history.jpg
• melting north pole ice
• anoxic oceans
• ocean acidification video