1) The establishment of DRUZHNAYA Station during 1974/75 and 1975/6 seasons. Having a Russian speaker on base (Graham Chambers), and an ex-Stonington Fid (Garik Grikurov) as Russian field leader, led to a warm and mutually useful relationship in the later years of the Cold War. We had hoped that this "warmth" would extend to being allowed to entertain female crew members on Base, but the Captain of the Kapitan Markhov gave a firm 'nyet' to the proposal ! It was noticeable how much better the Russian helicopters worked on decent BAS Avtur than they did on their own stuff !2) Winter 1975 was sandwiched by two bad reliefs, both involving N9 in their later stages. The February 1976 relief ( I am sure Captain Lawrence would testify !) would rank as one of the most difficult in the history of the Base, short of the ship not making it to Halley at all.
I'm not sure if 'near-misses' count as 'notable EVENTS', but as they still haunt the B/C's waking hours 30 years later, I'll add them here as a postscript.
a) A winter appendicectomy was narrowly averted when the patient responded to heavy doses of antibiotics. Doctor Eric Harvey was greatly relieved, naturally. However some other base members were actually looking forward to a bit of sealing-knife surgery, and were quite disappointed when the patient recovered.