Why call her Seatern?
My favourite sailing dinghy is the Seafly ; I still own and sail one. Before Seatern I had a Lightning 368 single hander which I called Seabee (Cb is the meteorological abbreviation for Cumulonimbus, the thunderstorm cloud). I thought of calling my BC20 “Sea Swallow” but there is one called “Gwennol -y-môr” which I assume means that (or something similar). But sea swallow is a sailor’s name for the tern – hence “Seatern“!