O’Brien’s voyage began and ended at the Port of Foynes, County Limerick, Ireland, where he lived.
[7] O'Brien's seagoing experiences were put to use in his design of the Ilen which was built for the Falkland Islands as a service boat.
O'Brien had some involvement with gun running in 1914 on behalf of the Irish Volunteers, for political reasons (he was a home ruler) and because he had experience in sailing.
On 26 July 1914, 900 guns were brought to Howth harbour aboard Erskine Childers' yacht Asgard.
The guns on Kelpie were transhipped to another yacht, Chotah, owned by Sir Thomas Myles, before being landed at Kilcoole in County Wicklow on 1 August 1914.
Later, during his circumnavigation 1923–1925 he planned to climb Mount Cook / Aoraki in the Southern Alps in New Zealand's South Island.
[11] O'Brien authored a number of books which document his experiences of sailing, from which he distilled advice for other boat designers, builders and sailors.