Many other crews were called out multiple times in one day, with Maraetai volunteers launching four times to attend to boaties that had found themselves in trouble.
Almost three-quarters of the 93 incidents were caused by mechanical, fuel-related or electrical issues.
Coastguard operations manager Ray Burge said that while Auckland Anniversary Weekend was busy they were bracing for an even busier Waitangi Weekend.
"We're urging boaties to make sure their boats are in good condition for a great weekend on the water, and have been well serviced before they head out.
"And even if the weather is scorching, make sure you've got your lifejacket on – they've never ruined a day on the water."