Totally not allowed and illegal!
Since this has been in the "news", the beach going public is fully aware of what's legal and what's not. Weddings are getting hassled and busted. Hopefully, it won't be your wedding!
The beach wedding industry nearly averted a total ban of all weddings and photography along the entire 4 mile Waimanalo/Makapuu beach coastline in 2016 and it could come up again.
Website wedding companies like this one, charging upwards of $2000+ who continue to display photos of set-ups like this and others on the beach sand near the water are the problem.
Don't "pay" to be part of the problem!
Chairs and arch set-ups are not allowed anywhere near the ocean or on the sand beach areas of any Hawaii beaches. They are only allowed in the tree-line and park areas. So why do them?
Better to have your guests stand for what is a 8-10 minute ceremony and spend your money on other services that have more immediate and lasting value like video, limousine, hair & make-up, flowers and lei i.e. just about everything else LOL!
FYI: If you are unsure, attach a photo from the websites you've seen photos from and ask the DNLR beach wedding permit administrator directly.
Go here: Steve.Molmen@hawaii.gov