SOLAS (Safety of Life at Sea) is an IMO treaty setting minimum standards for merchant ship construction, equipment, and operation to prevent accidents and save lives at sea. It has zero provisions on rights of transit passage, freedom of navigation, or overriding coastal state sovereignty in territorial waters or straits. Those issues are governed by UNCLOS (or customary international law for non-parties). Iranโs SOLAS membership doesnโt change territorial control over the Strait of Hormuz.