Nicholson says hooker Sam Johnstone was outstanding, while prop Tama Renton and Pone Kahotea also played well. The Mariners play the Northern Swords in Whangarei this Saturday, the start of a demanding seven days as they play Wellington in the capital next week.
"I think they will be better having got that first game out of the way. It is different at rep level, you get punished for mistakes.
"At one stage we made an 80-metre break and the ball got knocked out, it is those little things we have to get out of our game. Every game for us is going to be a good learning curve.
"We have to make sure we complete our sets and the individual players and the collective are focusing on that. When we have the ball, we have to make sure we do things well and then the defensive line needs to make sure they are talking."
The Swords beat the Manawatu Mustangs 24-20 to add to their 56-10 win over the Sharks in week one.
"The Northern Swords made it to the promotion game last year where they lost to Waikato," Nicholson says.
"It will be tough, we are going up there to win, but I want to see us improve."
Week two North Island Championship results:
Saturday, August 31:
Manawatu Mustangs 20, Northern Swords 24.
Coastline Mariners 30, Taranaki Sharks 25.
Draw for Saturday, September 7:
Norther Swords vs Coastline Mariners, Whangarei.
Taranaki Sharks vs Wellington Orcas, Hawera.
Manawatu Mustangs, bye.