$400 Million Worth of Hash
Given that hash is intended to be smoked, burning some doesn't seem to be a huge concern. However, hash is typically consumed for personal use at controllable dosages rather than in large quantities in an effort to elude police authorities.
Off the coast of Malta, traffickers were transporting 30 tons of hash in 2013. Most people call hash, a sticky substance, resin. It is created by pressing it out of specific marijuana plant glands, and is then often shaped into blocks. The street value of thirty tons of it would have been close to $400 million.
When the ship's crew realized Italian authorities were headed their way to meet them, they were 30 miles offshore. The team decided to burn their supplies because they were at a loss for a less spectacular escape strategy.