Gull-billed Tern and Great Knot

We couldn't end our stay in Queensland without a look at Cairns Esplanade, so before we handed back our hire car we stopped there for an hour or two. Although high tide was still several hours away, it was a big tide so the water was further in than we expected and most of the birds must have flown elsewhere. But a nice flock of about 30 Great Knot , with a handful of Bar-tailed Godwits and Whimbrel, were close to the walkway. This Gull-billed Tern flew in to dwarf them. I think this has now been split, as Australian Gull-billed Tern or just Australian Tern. It looks to me as though the bill is longer and sharper than on Gull-billed Tern, but I'm not sure of the id distinctions between them.