Complex sentence: A catamaran-based ferry service from Ilfracombe to Swansea has been proposed, but this service is not operational because adequate landing and berthing facilities in Swansea have not been forthcoming.
Split into simpler sentences: A catamaran-based ferry service from Ilfracombe to Swansea has been proposed. However, this service has been delayed because adequate landing and berthing facilities in Swansea have not been forthcoming.