A vehicle used by the pair was found parked at the Papanui Point car park.
Waikato Police Search and Rescue have been conducting searches in the area today, and a drone and Coastguard fixed wing plane are being used to conduct aerial searches.
Unfortunately search efforts are being hampered by extremely rough sea conditions in the area.
Police are appealing for information from the public to assist in the search operation and establish what has happened.
Police would like to hear from anyone who may have been fishing in the area, may have seen these two men or witnessed anything of note on Sunday.
Anyone with information which may assist is asked to contact Police on 105 and quote file number 211101/6076.