The title might be slight exaggeration, but at low tide you can indeed walk across at least a part of Loch Indaal. This is from an Islay walking week a few years ago. We started at the Gaelic College just outside of Bowmore and walked across to where the River Sorn runs into the loch at Bridgend. Also note the (hazy) Paps of Jura on the right.
A view over Loch Indaal to Bowmore on a dark yet light night. The Moon breaking through the clouds just provided enough light to illuminate the loch on the November evening I took the picture. The view is from the top of the pebble beach at Blackrock over to Bowmore.
A classic view in Bowmore, the unofficial capital of Islay. The view is from the pier over to Bowmore distillery on the shore of Loch Indaal. The Rhinns of Islay on the right in the distance. If memory serves me right taken on an October afternoon.