Are there any retailers in Australia?

Their online shop has international shipping but seems pretty expensive, although there is a message to contact them to check the cost.

Their website has a seller in Australia but broken website.

Jonathan Lafforgue use to be the primary importer of HSM products.
and the link probably sent you his now defunct site

Gareth Leggett use to dabble in importing HSM also.

I don't think Jonathan has been involved since 2018 according to his FB Page
www.facebook.com/p/Hot-Sails-Maui-Australia-100057365563247/

Garreth has apparently has also left the WS community.

I don't think any body took over

Jeff wasn't in a hurry to find a new Aussie retailer when I contacted him last year to buy a mast. I just buy directly from him. He's a small brand, and people who want his brand will seek it out. Jeff is the most open door and easiest owner/director I have dealt with in the Windsurfing industry. Nearly all of them won't give me the time of day. He has supplied me battens and cams for current model, non HSM sails when the OEM's have turned their back on me. So, I don't mind paying the extra $$$, and having to pay import duty.

I was recently looking for a speed freak to use with my LT, (forum topic on here somewhere). The buy price from Jeff was fine but the freight from Maui was a killer. I ended up buying a brand new unused sail from that Leggett bloke in SA but the only way he would freight it was with pack'n'send and that was extortionate. I will never use pack'n'send again, a complete rip, don't know how they survive as a business.