There are several activities related to ocean sciences; the projects are interdisciplinary and can be adapted for use at different grade levels. The projects using maps are especially well written.
This site offers a very good overview of how to do a science project, including information on keeping a lab notebook
This is a virtual expedition to a hydrothermal vent area from a mission completed in 2002. There are some excellent pictures and great resources on marine geology. In the resources, there are several suggested activities.
There are several different satellite tagging projects here where students can track different marine mammals. Background information is very good on how such organisms are tagged and tracked.
These are some interesting puzzles and games for kids. Some require Flash while others require JAVA. The puzzles are timed.
This is a nice glossary of words that you will find associated with many aquarium books, videos, and magazines.