"We haven't made the decision yet but we will certainly be looking at putting up a big stainless steel grate.
"That's the likelihood as we can't go on replacing the glass.
"Council will be deciding what to do soon, obviously we have to start looking at some kind of stainless steel replacement."
NCC had worked hard to bring "vibrancy and vitality" back to the city and it was extremely disappointing to have acts of vandalism like this continue to occur, he said.
"It's a crying shame, the whole concept of the viewing platform is about having the glass end looking right out to sea."
Many people expressed their disappointment on Facebook as well as theories that the glass had not been smashed intentionally but by stones flung up by waves.
However, this could not have been the case and the smashed glass was definitely an act of vandalism, Mr Dalton said.
Council chief executive Wayne Jack said having a metal barrier would defeat the point of the platform but it would have to be considered.
"It's extremely disappointing ... a real shame.
"We're just going to have to assess what we're going to do.
"It is toughened glass and would take a huge amount of effort to break, it was not an accidental break."
The glass barrier was initially one panel stretching across the full length of the platform but when it was first smashed three months after opening it was replaced by three panels to minimise cost of future vandalism.
The large single panel would have cost more than $5000 to replace but one smaller panel was about $1300.
Earlier this month the viewing platform concrete was scorched from a fire underneath it.
However, the small blaze, on October 10, was believed to be a rubbish fire rather than a deliberate act of arson.
Other areas of Marine Parade have been targets of vandalism including the nearby Veronica Sunbay which has had its windows (installed to create a windbreak for comfort) taken out following repeated vandalism.
To prevent further vandalism in the area people are encouraged to report anti-social behaviour immediately.
The maximum penalty for wilful damage is three months' imprisonment and/or a fine of $2000.
The viewing platform, which opened in December 2015, was designed by Napier architect Graham Weaver as a tourist attraction and for aesthetic reasons to obscure view of a stormwater outfall.
