"As numbers grow, it's more important that everyone keeps following the rules if we're gonna try keep everyone safe," he said.
Since October last year, the harbourmaster team had spoken with 3000 water users out on lakes and ocean in the Bay of Plenty.
Of those, 277 people had breached the Bay of Plenty Regional Navigation Safety Bylaw 2017, with 157 being stung for speeding.
To date, 20 infringements had been issued with more breaches still being processed.
The fine for infringements was $200.
He said offences relating to speeding in 5 knot areas and lifejackets were common, with jet skiers overrepresented.
"I can't believe in this day and age we've found 55 vessels so far this year that didn't have lifejackets or enough lifejackets on board.
"You'd think that would've been history but it's still happening."
Breaches relating to the naming of vessels and registering of jetskis were also common.
This was the last year since the bylaw was implemented that water users who had not registered their jetski or named their vessel would be allowed a grace period.
Currently, people were given two weeks to register their watercraft and escape a $200 fine.
The local harbourmaster team would be out on the water this weekend for Maritime New Zealand's "No Excuses" campaign which targets recreational boaties who are not carrying or wearing lifejackets and who speed on the water.
Coastguard Rotorua president Richard Packham urged people to get equipped for the water.
"No one ever has their day ruined by wearing a lifejacket," he said.
He said more people were beginning to wear lifejackets, but there were still issues with people wearing incorrectly fitting jackets.
Having a waterproof communication device was important, "even having a cellphone in a waterproof bag," he said.
Checking the weather was also vital, he said.
"Lake Rotorua is a classic example. There are lots of hills around it so people think it is nice and calm, so they head out [on the water]. But when they get out of the shadow of the hill, it gets really rough and they get caught out," he said.
"Enjoy your time out there but respect the water."