What sound signals will you hear if a sailboat is underway in the fog?

If a sailboat is underway in fog, you will typically hear one prolonged blast every two minutes, which indicates the vessel is moving. Additionally, if the sailboat is under sail, it may sound a short blast followed by a prolonged blast. If it is using its engine, it may sound two short blasts. These sound signals help other vessels determine the sailboat's status and location in low visibility conditions.