Any ideas on a science experiment involving the ocean and scuba diving?

Question

My daughter has to do a science experiment this summer for school. Yes homework over the summer. She is 11 and is going to take a beginner scuba diving lesson in Mexico with a dive master. I am a certified diver and will be with her. We will be doing a shallow dive. Can anyone think of a experiment we can do involving the ocean and scuba diving. She is supposed to do her experiment on something she wanted to learn about. She is very excited about doing a (beginner) scuba diving class. (For those wanting to warn me about my daughter being 11 and diving, I understand the concerns. She is on the swim team and is a very strong swimmer, she is also big for her age at 5 feet tall and 110 pounds. I won't be leaving her side).

We would like a easy experiment involving the ocean, any ideas?

Answer 1

do something with ocean currents or something, underwater power generation? that might be too hard

Answer 2

"atmospheric pressure on objects"  take an ordinary styro-foam cup as low as she can.  at 140' the cup will be crushed to the size of a thimble.  (she can stop anywhere along the way.)

Answer 3

1. you could talk about the diversity of life underwater.

2. you could talk about the difference in pressure or temp at that depth

3. you could talk about how the bends happen

4. you could talk about buoyancy

Answer 4

Actually, the color absorption investigation is a pretty good one.

Captain Don Stewart launched commercial tourist SCUBA diving around Bonaire (she can read all about him; he was a very colorful character).  This was back at a time when divers didn't use gauges.  No pressure gauge, no depth gauge (!)

What Don Stewart did was tie a piece of red ribbon on to divers.  The instruction was: when the ribbon appears black, don't go any deeper.  It would be interesting for your daughter to compare apparent color of a red ribbon to actual depth as reported by her gauge.

Answer 5

The principle advantage of SCUBA is being able to go deeper under the water than most people do.  The principle changes are in pressure and light.

As you get deeper frequencies of light get absorbed.  first red, then blue.  Take a colour wheel underwater and watch as the colours disapear the deeper you go.

Or fill a balloon with air on the surface and watch it get smaller and smaller the deeper you go.  Conversely, you could fill a balloon up with air when you are at depth, and then watch it expand as you surface.  It may even pop!

Answer 6

Light absorption in the ocean.  

http://oceansjsu.com/105d/exped_briny/13...

She can use an underwater camera and take pictures of a white plate as a function of depth.  This will record how "blue" it gets.  She can plot the change in color (which you can extract from a digital image by looking at the RGB values in a program like Photoshop) as a function of depth and see if that matches what theory would predict for seawater alone.  Deviations from theory would represent biological activity and absorption by chlorophyll.  

I know it doesn't sound all that easy, but it would be, and nobody else will think of it.  It can also be done for relatively shallow water dives.  You would start to see the effect after only a few meters, if you could go down to 10 m, which I think is still a "shallow-water" dive, you would get some pretty cool data.  

note:  The change in color would be represented by a decrease in the "red" intensity.  Near the surface, for a white plate, red, blue and green will be nearly equal.  As you descend, red will decrease relative to blue and green.  Plotting ratios of red to blue or green will give you an estimate of the absorbance of the water.

Answer 7

Since she's just learning about scuba, then maybe learning about the body's affects when diving would be an interesting topic.  She can learn about how the body compensates for changes in pressure, and what happens when those no longer work.