British landing craft were transported by ships called LSI, or Landing Ship Infantry. These were typically converted passenger ships or ferries, which launched their landing craft from davits (cranes) along the side of the ship. The process of lowering and launching the landing craft took place at a designated point called the Lowering Position. This was roughly seven nautical miles offshore, far enough out from the beaches to avoid mines, German coastal guns and shoal waters. The typical British landing craft, the Landing Craft Assault (LCA), had a top speed of about six knots when loaded with troops. As such, the journey took a little over an hour. The troops would typically be in the boats for longer than this, though, to allow the landing craft to get into formation. Rough seas could also cause delays, though these were not serious on D-Day. Larger landing craft, like the Landing Craft Tank (LCT), were not carried by landing ships, but instead made the whole journey across the Channel under their own steam. They might spend ~20 hours at sea, depending on when they were to land.