Moored of the VYC at Watsons Bay. Sorry for bad photos, looks kind of nice, long and low, and it's red so must be fast.

With a knuckled bow and stern like that including steep run up to the stern from the waterline ending it could be a 5.5m or even 6m with cabin added. Not a bad job if so. Or a 1/2 scale hull of an old 12m - Gretel II? - used in tow trials like was done for the Advance program? with deck and cabin added etc. Have done a search of VYC results in the open yacht division but no yachts sailed in their 2022 regatta. Someone local to VYC will know?

A couple more pics, only had phone so poor resolution from the shore, zoomed right in. Name on the topsides near transom is LOKT IN.
I didn't notice the bow knuckle untill you pointed it out. It would be interesting to see what the underwater profile is like, that would give a few more clues.

The white boat in front is probably a 5.5.

I agree the knuckle bow looks very metre'ish, but it's also got a bit too much freeboard for a 5.5 or 6m.

Maybe a one off that came out of a 5.5 mold or plug?

From google maps but not much better resolution. You can see the other 5.5 though...
Edit: Seabreeze sucks if you just want to drop a pic into a post

www.google.com.au/maps/@-33.8445076,151.2817185,3a,15y,272.22h,88.36t/data=!3m6!1e1!3m4!1sUonFfO47FDMoGOZUA4YEPQ!2e0!7i13312!8i6656

Probably a long shot but could it be this with a cabin added? "Pacific Highway". Realise the for sale advert is in Europe...............but it was originally built here...........the bow knuckle of the yacht in the below link looks further out of the water than the boat in the OP but with the extra cabin weight and other weight this may account for it...........the sterns look very similar..........

www.racing-yachts.com/modern-6mr-267.html

As per Jethrow maybe someone took a plug off it and made a one-off with cabin.

I've had a look at it before, and I smugly decided I'd spotted it as a Safir, a production boat from Sweden that was a 5.5 with a lid. Now I've seen the pics I realise the Safir doesn't have a bow knuckle and the tiller is in a different position. Damn. I'm crushed.

When I've seen it up close it looked very, very much like a 5.5 hull, being much lighter and a few feet shorter than a 6 Metre and IIRC the rig is more 5.5-ish. I see on the 5.5 Metre class' site that there's a Hudson (Sydney) built Lexcent 5.5 with a very similar bow knuckle and transom shape, so perhaps Hudson did another one with a lid.

It's a very attractive boat seen from the shore and from up close.

I say we nominate Jethrow to ask around the Pittwater 5.5 fleet and tell us what he finds out.

Yeah Chris I've been asking around but my regular contacts are all on their way to Norway for the 5.5 Worlds.
I'll keep asking though...