All consumable food and equipment are brought to Diego Garcia by sea or air, and all non-biodegradable waste is shipped off the island as well. From 1971 to 1973, United States Navy LSTs provided this service. Beginning in 1973, civilian ships were contracted to provide these services. From 2004 to 2009, the US-flagged container ship MV ''Baffin Strait'', often referred to as the "DGAR shuttle", delivered 250 containers every month from Singapore to Diego Garcia. The ship delivered "more than 200,000 tons of cargo to the island each year". On the return trip to Singapore, it carried recyclable metals.