Complex sentence: The two new vessels, and are 49,000 gross tonnes and 210 metres long making them the largest ferries to operate in the English Channel and were the first passenger ferries in the world to comply with the new SOLAS "Safe Return to Port" requirements.
Split into simpler sentences: The two new vessels, and, are 49,000 gross tonnes and 210 metres long, making them the largest ferries to operate in the English Channel. They were the first passenger ferries in the world to comply with the new SOLAS "Safe Return to Port" requirements.