Complex sentence: Boyd's eldest son Sir Walter Herbert Boyd, 2nd Baronet, is still remembered in the sailing world as the designer of the "Howth 17th Footer" yacht, while his second son Dr. Cecil Boyd was a noted rugby player.
Split into simpler sentences: Boyd's eldest son Sir Walter Herbert Boyd, 2nd Baronet, is still remembered in the sailing world as the designer of the "Howth 17th Footer" yacht. His second son Dr. Cecil Boyd was a noted rugby player.