Mr Dalton said the council had received "advance notice" they might be invited to a celebration of this event by Napier's sister city in Victoria, British Columbia.
"If we do get invited and go over it would make sense for us to do ... both things with one trip," he said.
When asked how much this would increase the trip's cost, Mr Dalton said costs "may go up a fraction", but would be offset as the group would be hosted by the city.
Despite having the sister-city relationship with Victoria for decades, the first mayoral trip to centre was only made in 2012 - to celebrate the city's 150th anniversary.
Mr Dalton said the celebration was to be held in May. If the trip to Canada did not work out, Mr Dalton said the aquarium trip would remain scheduled for that month.
On the trip he and staff would be visiting, researching and developing partnerships with four facilities between the Monterey Aquarium/Monterey Bay Aquarium, California Academy of Sciences, the Aquarium of the Pacific and Birch Aquarium at Scripps.
When they were approved, Mr Dalton's expenses were expected to cost a total "higher estimate" of $6170. The bulk of that cost - up to $3200 - would be for international flights, up to $2500, and domestic flights, $700.
Estimates put additional costs at $2100 for accommodation, $600 for meals and $270 for car hire.