The first burst of waves would be the most powerful and have the longest intervals between them.
Whanganui is not in the perfect southwest alignment to catch the biggest waves. South Taranaki is better placed for them, Ms Clark said.
Forecasters had warned boaties against crossing the bars of west coast rivers, and Coastguard Wanganui leading radio operator Pam Gilligan was surprised how many were out fishing yesterday.
The Coastguard boat was called out about midday, but president Garry Hawkins said that was to tow in a boat that had broken down, and not a rescue.
Even if the big ones never hit, Matt Edmonds said surfers had a great time yesterday.
During the calm weather there was little surf, so "wave-starved" surfers were all agog at indications a swell was coming. It came yesterday.
"It started really early this morning, very clean and very big, a really fast-moving swell. We have had a really beautiful surf today," he said.
The waves were only 1m -1.5m high, and were good at Morgan St and Karaka St beaches. There may be more to come.
"There are some very excited surfers in this town. They're frothing. There's a lot of talk and texting and looking going on. It's fun times."