Last weekend, an A330 was sunk 75 feet under the Aegean Sea to become the largest plane ever used for an artificial reef. It took 2 1/2 hours for the 36-year-old jet to submerge. Turkey purchased the plane from a private company for $92K.
From The Washington Post:
Özlem Çerçioğlu, mayor of the local Aydin province, told AFP the motivation for sinking the plane was twofold: to turn Kuşadası into a year-round destination for tourists who dive, and to protect the underwater life. “And with these goals in mind,” she said, “we have witnessed one of the biggest wrecks in the world.”