Trafalgar Point was named in 1834 by the officers aboard the surveying ship, HMS Alligator, in memory of the Battle of Trafalgar.
Nile Head was also named by the HMS Alligator, in memory of Lord Nelson’s success in the Battle of the Nile, Aboukir Bay, when he defeated Napoleon Bonaparte’s fleet in 1798.1
As with many localities on Rangitoto ki te Tonga / D’Urville Island, Nile Head boasts unmanaged stands of the exotic tree, pinus radiata. These trees, originally planted as woodlot or shelterbelts are now of serious ecological concern as they dominate the landscape and prevent the regeneration of native bush. Active management of these trees is currently being undertaken by the Marlborough District Council and partner organisations, such as the Marlborough Sounds Restoration Trust.2
Otu Bay is probably named for the Māori word for washboard. An otu is the part of the waka (canoe) that is connected to the prow and prevents the waves that hit the bow from washing into the boat.
It is likely this name was applied to the bay due to the long peninsula of land that runs out to Bottle Pont, on the south side. This peninsula provides a figurative washboard to the bay, protecting it from heavy winds and seas from the south and south-west, preventing large waves from breaking over the beach.3
2. Andrew Macalister, “Management Plan: Wilding Exotic Trees on d’Urville Island, Marlborough Sounds”, Marlborough Sounds Restoration Trust, accessed, July 2, 2018, https://static1.squarespace.com/static/51a82c3ce4b080a0192d23d2/t/51b82771e4b049e6ffb43154/1371023217828/Management+Plan+-+d%27Urville+Mar11+MSRTwebsite.pdf .
3. I. W. Keys, “The Cultural Succession and Ethnographic Features of D'Urville Island”, The Journal of the Polynesian Society, 69 (1960), accessed April 24, 2018, http://www.jps.auckland.ac.nz/document/?wid=3081 .