I think there is a difference between windsurfing and paddling.
Anybody can jump into a kayak or SUP and try it. Often including people who can't swim. People who can't swim are candidates for drowning.
People doing windsurfing can most likely swim as they need to be able to get to their board when they fall off.
People can drown just as easily within 400m from shore or further out of they can't swim. Or even drown in a paddling pool. Further out would probably give less chance of making it back to the beach if in trouble. But there is the board for floatation.
How else can a drowning occur if you already know how to swim? Getting hit on the head by a board? In that case the new laws should include mandatory helmets for all people leaving the beach. Including swimmers to protect themselves from stray surfboards in unpatrolled beaches.

John340 said..
In the end, we are adults and don't need the government to tell us what to do. .....

On that point, I would recommend if there is a group/s that represents windsurfers & kiters in WA they would do well to approach the newly elected Member of the Legislative Assembly, Aaron Stonehouse from the Liberal Democrats Party. The Liberal Democrats are all about 'less government', and opposing the Nanny State culture. Aaron may be in a position to block this proposed policy change as it goes through the Legislative Assembly, providing he is supported by several other Independents.

The Lib Dems love this sort of stuff, they exist for it.

WWA/KSWA/RLSSWA etc.. were all invited to provide input & guide the review on the original discussion paper.

www.transport.wa.gov.au/mediaFiles/marine/MAC_P_Discussion_Paper_Summary_Safety_Equipment_Review.pdf

This was then summarized and put to the public for comment (Survey)

app.surveymethods.com/EndUser.aspx?F3D7BBA3F6B5AEA7F1

All information will then be analysed in Phase 2 by the DoT and assisted again by the external reference group with a second survey then released for review to the public before finalising the paper for release.
Hopefully there is some commonsense and agreement within the Reference Group.