After the 2004 Indian Ocean Tsunami which killed almost 230,000 people include Aceh province in Indonesia, United States NOAA (National Oceanic Atmospheric Administration) place hundreds of these kind of buoy in the pacific ring and indian ocean. This buoy is a transmitter relay from the seabed sensor below the ocean which transmit signal warning if there's a signs of tsunami trigger earthquake to the NOAA satellite and in the end it will be widely spread to warn people who live near the shore of imminent potential tsunami to quickly evacuate to the save area.
Indonesia also have our own Tsunami Warning System buoy as well as German help for Tsunami buoys in the shore of Mentawai and a long West Sumatra shore, but some of them were already broken or under repaired when the recent tsunami disaster happened (2010). It's very sad more of 400 people are still missing, and the clever governor went to Germany when his people still needs help, very clever.
This papercraft is already simplified, only 1 page with 1:35 scale. I think this model might be useful for education.