More details are becoming available on US Navy plans to convert the Trident missile submarines Michigan and Georgia into cruise missile and commando submarines. Plans call for the replacement of missile tubes 1 and 2 with airlocks, each of which could accommodate nine SEAL commandoes. As these airlocks are shorter than the missile tubes they replace, a bunkroom for 66 SEALs will be installed on the lower deck. The elaborate navigation system needed to launch precision nuclear missile strikes will be replaced with a more compact system, leaving space to create a SEAL mission planning office. The other 22 missile tubes would be designed to accept canisters of seven Tomahawk cruise missiles, allowing the sub to carry up to 154. In common usage, however, the Navy expects to carry only 140 missiles, using tubes 3 and 4 to carry extra equipment for the SEALs. The subs will be flexible, however, and could be sent on some missions without any SEALS on board and on other missions without any missiles. The conversions will start in 2003 and the first sub should be ready for tests in 2007 and rejoin the fleet in 2008.--Stephen V Cole