The free period has been reduced from half an hour to 15 minutes at Navigation Point and has left businesses in the area concerned for their livelihoods.
The new charges will see motorists wishing to park for 24 hours facing an increase from £6 to £8.
The car park has also been made cashless – causing worries that it will be less accessible for certain motorists.
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Northwest Parking Management, which runs the car park, has said the cashless machines were installed following complaints concerning the reliability of ticket machines and that a new entrance sign advises drivers of the changes.
It added that the new machines have larger keypads which are more user friendly for drivers.
Business owners have said they found out about the changes after they saw signs go up on Tuesday.
People working at the Marina have also described witnessing motorists drive away after seeing the new sign.
Lock Gates owner Ken Hedley told the Mail that business on Wednesday was “bad”.
He’s also described customers struggling to pay at the machine following the changes.
"We’ve had about 10 tables today. Normally, today, I would’ve had about 60 tables,” he said.
“It’s unbelievable. It’s people getting out, spending 10 or 15 minutes at the car machine, trying to put money and then getting back in the car and driving out.”
He added: “That just goes to show how empty it’s going to be.
"You just can’t imagine how dead it is down here today.”
The reduction in the free period has also raised concerns about deliveries.
Angela Brumwell, owner at Bar Central, has explained deliveries to the business come through the car park as the bar has no back entrance.
"I’ve got trucks coming in and if they’re not out and unpacked withing the 15 minutes, it’s going to affect us big style.”
She continued: “The Marina will die on its backside if somebody can’t help us.
Looking ahead to next year’s Tall Ships Races, Angela added: “There might not be any businesses down there for the Tall Ships.”
Darab Rezai, the chairman of Hartlepool Licensees Association, added: “It doesn’t just affect businesses. It affects the tourists who are coming in the town, it affects those people who come to see their relations in the flats, it affects those people who want to walk about and it affects all those families and all those people that have got to count every penny.
"It affects the whole town.”
Adam Gaines, who runs Rosie’s pub, added: "I just find the whole thing disgusting. I can already see that the new charges and the reduction of the free period is having an effect on businesses. People are just turning away.”
Northwest Parking Management said in its statement: '”The tariff on Hartlepool Marina car park has not been increased in over four years.
“The ‘Under 30 minutes free’ has been reduced to ‘Under 15 minutes free’.
"This could have been reduced to ‘0 minutes free’ as the British Parking Association only requires a 10-minute grace period within their Code of Practice.”
It added that “the banking system’s push for a cashless payment system post Covid” was also a factor in the new machines.