Sound of Mull

The diary is written by the tide rather than the clock. Skippers work two dives a day around slack water, which can mean a first shot line before most people have had breakfast and a second in mid-afternoon, or both bunched into the middle of the day. The boat shots the wreck, teams go down and up the line, and everyone surfaces under a delayed SMB with the stream already building. Live-aboard hardboats are common on this coast and move along the Sound with the weather instead of running out and back from one port each day.

The Sound is a glacially cut channel with steep sides, and the ships lie on the slope rather than on a flat bottom, so depth changes as you swim a hull: the shallow end can be relaxed while the deep end needs gas and a plan to match. The bottom itself is soft, and a team that drops off the structure ends up in silt with nothing to look at. Away from the steel there are drift walls along the shores, kelp on the shallow shelf and sheltered reefs held in reserve for when the tide is wrong or the forecast closes the open water.

How much of a wreck you actually see is a matter of torchlight. Red is gone long before working depth here, so plating reads grey-green until a beam lands on it and the colour comes back. The hulls also differ more than a site list suggests: the losses span the 1880s to the 1950s, riveted iron at one end of that range and heavier steel at the other, and they run from structures you swim over to collapsed ribs and loose plating better crossed than entered. Photographers plan around the growth and the angle rather than the ship's name.

This is an advanced destination and honest about it. Beyond the obvious kit, the things that decide whether a trip works are unglamorous: being back at the line when the skipper said, holding a stop in a moving stream, and planning gas for a hull that gets deeper the further you swim it. Divers without decompression training can still fill a week on shallower structure and reef, but they will sit out the headline dives and should say so when booking rather than on the boat. Anyone still learning buoyancy in a drysuit will get little back from the Sound.