An Indonesian shipbuilder (PT Ludin) with links to Swedish builders has adapted the Swedish CB90 fast patrol boat to a design better adapted for use in tropical waters. The first design was the X15 which was very similar to the 20 ton CB90. A smaller version of the X15, the 10 ton X12 has proved very popular in Indonesia and now Bangladesh, where a local firm is building 18 under license from PT Ludin. The X12 has a top speed of 63 kilometers an hour and is 11.7 meters (38 feet) long and 11.4 feet wide. They can operate in shallow (one meter/three feet deep) water and are usually armed with two machine-guns and small arms. The coast guard versions have a radar and a crew of six or more sailors. These boats cost less than $100,000 each.