Police are appealing for any information after two men failed to return from a fishing trip near Raglan.
The pair, aged 52 and 44, left their home near Hamilton on Sunday morning to fish off the rocks at Papanui Point.
The men were expected to return home on Sunday evening but after failing to show the pair were reported missing at 11pm.
A search and rescue operation was launched over Sunday night and a vehicle used by the men was found at the Papanui Point carpark.
"Waikato Police Search and Rescue have been conducting searches in the area today, and a drone and a Coastguard fixed-wing plane are being used to conduct aerial searches," a police spokesperson says.
"Unfortunately search efforts are being hampered by extremely rough sea conditions in the area."
Police are appealing for anyone with information about what might have happened to come forward.
"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."
