Sinking ships for wreck diving sites

Sinking ships for wreck diving sites is the practice of scuttling old ships to produce artificial reefs suitable for wreck diving, to benefit from commercial revenues from recreational diving of the shipwreck, or to produce a diver training site.

To prepare a hulk for sinking as a wreck site, several things must be done to make it safe for the marine environment and divers. To protect the environment, the ship is purged of all oils, hydraulic fluids, and dangerous chemicals such as PCBs. Much of the superstructure is removed to prevent the hazard of it eventually caving in from corrosion. Similarly, the interior of the ship is gutted of all structures that corrode quickly, and would be dangerous to divers if they came loose. The ship is thoroughly cleaned, often with the help of volunteers interested in diving. A significant part of the cost of preparing and sinking the ship comes from scrapping the contents of the ship, including valuable materials such as copper wiring. The hulk's suitability as a diving site is enhanced by cutting openings in its hull and interior bulkheads to allow divers access.

The preparation phase removes a significant amount of weight, so the ship sits higher in the water than normal. The ship must be carefully weighed down by filling some sections with water as makeshift ballast tanks to prevent excessive rolling in port or during towing. The ship is towed to the sinking location, usually in shallow waters. The ship is scuttled using dynamite, in a controlled demolition. The holes are blown so that the heavier engine room and stern floods first, then the rest of the hull. The aim is to sink the ship in an upright position.

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Wikipedia