The first person on my list of contemporary solo circumnavigators within my lifetime is Chay Blythe. When I searched for information I found http://www.chayblyth.com/ and http://en.wikipedia.org/wiki/Chay_Blyth so you can check those out if you want more information.
Sir Charles Blyth, CBE, BEM (born 14 May 1940), known as Chay Blyth, is a Scottish yachtsman and rower. In 1971, Blyth became the first person to sail non-stop westwards around the world, aboard the yacht British Steel, taking 292 days, and as a result was made a Commander of the British Empire (CBE).
Most people are thinking about taking it easy when they get to their 70s – not Chay! Chay and his wife, Felicity, will be taking their new yacht Wullie Waught round the Mediterranean, the Canaries and then on a three year trip round the world. Good on him!