NOAA, the National Oceanic and Atmospheric Administration, has an online games arcade for elementary and middle school students. There are sixteen games currently on the site and NOAA is advertising for a soon to be released seventeenth game. Most of the games have an oceanic and environmental science theme. The games are formatted as scavenger hunts, puzzles, and simulations.

One of the games that I tried was the Nautical Chart Scavenger Hunt. In this game players have a list of items to find on the nautical chart. When an item is located on the chart players have to drag it on to the list.

Applications for Education
The NOAA games could be useful for introducing or reviewing a unit of study about Oceans.

Here are some related resources that may be of interest to you:
Ocean of Know
Live Ocean Cams
Tour 3D Ship Models in Google Earth