Port chief executive Garth Cowie said it would "future-proof" the port.
"Shipping patterns are changing, and larger vessels are projected to visit New Zealand. At the same time, volumes are set to increase considerably," he said.
"We have already made significant investments to build capacity and increase productivity, but in our peak season there is a maximum capacity the port's main container berth can handle.
The start of the project would be tied to need.
"We're not certain of when that will be but we do know that we need to be ready to start work immediately if required to remain the port of choice for central New Zealand.
"If we are not ready shipping lines and cargo volumes could go elsewhere, resulting in increased costs in the supply chain for our local exporters and importers.
"It is quite an exciting opportunity and it will certainly make sure we can continue to be part of exporters' supply chains."
Cost for the inter-generational asset was yet to be determined, with the volume of required dredging unknown.
"A ballpark figure is probably more than $50 million and my gut feeling is less than $100 million.
The new wharf will accommodate ships longer than 300m, enabling the port to berth two large cruise ships simultaneously, but the trend was towards wider ships.
Napier Port has already accommodated ships too wide for the Panama Canal and recent crane purchases, part of a $34 million spend following 2014 harvest delays, could easily work with wider ships.
Doug Ducker, managing director of the port's biggest customer, Pan Pac Forest Products, and board member of regional economic development agency Business Hawke's Bay, said any strengthening of infrastructure that helped exports was welcomed," he said.
"The key thing is being able to get in the best commercial vessels and get the turnaround of those vessels, because they only cost money when they are in port. They make money when they are sailing between destinations.
Napier Mayor Bill Dalton said it was "superb" news for the region's port city and good news for growers.
"I think we are absolutely privileged in Hawke's Bay to have such a well-run port which has an incredibly strong governance team and proven management team."
Owned by the regional council, it is the fourth-largest container terminal in New Zealand, processing more containers than Wellington, Nelson and New Plymouth combined.