Roseneath resident Holly O'Rourke, 12, said she was excited by the birth and hoped the couple would call their first-born Jack.
"They're a nice couple, I made a Facebook video of the gun salute," she said.
Her grandmother, Christina Speirs, preferred the names James or George.
"We usually watch the salutes from home because we look over Point Jerningham, but we decided to come down today," she said.
Another resident, Lou Hunt, said she had the day off work after her building needed further structural inspections after Sunday's earthquake.
"I've always wanted to see the salute live."
Lieutenant Doughty said the guns were kept at Point Jerningham permanently for salutes.
" It's historically been the location of gun salutes, because it points out into Wellington."
The royal birth had been the talk of the last few weeks, he said.
"We are pretty excited about it. It's always good to see a new baby being born."