Complex sentence: BM1 Bernard Webber, EN3 Andrew Fitzgerald, and SN Richard Livesey plus SN Ervin Maske, who volunteered for the mission even though he was assigned to Stonehorse Lightship and just happened to be at Chatham awaiting transportation to his lightship.
Split into simpler sentences: BM1 Bernard Webber, EN3 Andrew Fitzgerald, SN Richard Livesey and SN Ervin Maske. Maske volunteered for the mission even though he was assigned to Stonehorse Lightship and just happened to be at Chatham awaiting transportation to his lightship.