"It's obvious that these thieves are targeting local boats and they will not hesitate to take anything that literally isn't tied down," he said.
"If you own a boat, make sure that you remove as many items as possible when it is not in use, otherwise you will be sending an open invitation to thieves.
Mr Sloan said thefts from boats are not unusual at this time of year as holidays approach.
"If you are offered any cheap boating gear such as motors, fuel tanks or batteries, please think twice about where it may have come from. It may seem like a bargain, but once again if it seems too good to be true, it's probably stolen."
If you are offered any cheap boat gear or if you know anything about the weekend thefts, contact Intel at HB Police on 06 831 0700.
Information can also be left anonymously on Crimestoppers 0800 555 111.