its submarines or motor torpedo boats to deliver agents or equipment. Submarines were regarded as too valuable to risk within range of enemy coastal defences. They could also carry only small numbers of agents, in great discomfort, and could disembark stores only in small dinghies or canoes, which made it difficult to land large quantities of equipment. SOE nevertheless used them in the Indian Ocean where the distances made it impracticable to use any smaller craft. The vessels used by SOE during the early part of the war were clandestine craft such as fishing boats or caiques. They could pass muster as innocent local craft and carry large quantities of stores. They also had the advantage of being largely outside Admiralty control. However, SOE's first small craft organisation, which was set up in the Helford estuary in Cornwall, suffered from obstruction from SIS, which had a similar private navy nearby. Eventually, in spring 1943, the Admiralty created a Deputy Director of Operations (Irregular), to superintend all such private navies. This officer turned out to be the former commander of SIS's craft in the Helford estuary, but his successor in charge of SIS's Helford base cooperated much better with SOE's flotilla. While SIS and SOE (and MI9) landed and embarked several dozen agents, refugees and Allied aircrew, it was impossible to transport large quantities of arms and equipment inland from beaches in heavily patrolled coastal areas, until France was almost liberated. After the German occupation of Norway, many Norwegian merchant seamen and fishermen made their way to Britain. SOE recruited several to maintain communications to Norway, using fishing boats from a base in the Shetland Islands. The service became so reliable that it became known as the Shetland Bus. One of its boats and crews launched a daring but unsuccessful attack ("Operation Title") against the German battleship Tirpitz. A similar organisation ran missions to occupied Denmark (and neutral Sweden) from the east coast of Britain. The "Shetland Bus" was unable to operate only during the very long hours of daylight in the Arctic summer, because of the risk that the slow fishing boats would be attacked by patrolling German aircraft. Late in the war, the unit acquired three fast Submarine chasers for such missions. About the same time, SOE also acquired MTBs and Motor Gun Boats for the Helford flotilla. SOE also used feluccas to maintain communications between Algiers, and southern