I would not dispute the fact if you had the body and strength of an elite athlete ,expierenced in bodysurfing and the calm presence of an SAS
recruit to assess the situation a PDF or even a safety harness may be more of a hinderance however for the normal norm even on tenders it can be problematic climbing back in solo especially the older tenders with a fair degree of tumblehome . Unfortunately the law must cater to everybody including Chinese tourists.
On older IOR boats with a fairly high freeboard and a lot of tumblehome the difficulty of being hauled back in on the move is one hell of an effort especially if the person is tethered near the bow. Try it.
After all that is said as a younger man I never bothered with a harness unless it was rough or at night and never used the life jacket . Thank god the only time I fell over I was harnessed and had a crew.

All@Sea said..
So let me get this clear, in NSW, if I were to swim to an anchored vessel and climb aboard via a tender tied alongside I could be fined, but if I haul myself up the anchor chain or onto the transom I'm In the clear?

How about if I were to (for arguments sake) swim to the boat towing my wife in a small tender without a PFD... would she be fined?

"If the law supposes that," said Mr. Bumble, squeezing his hat emphatically in both hands, "the law is a ass - a idiot. If that's the eye of the law, the law is a bachelor; and the worst I wish the law is, that his eye may be opened by experience - by experience." (en.wikiquote.org/wiki/Oliver_Twist)

Only if your boating ,so is using the tender as an aid to boarding boating.
She would probably be congratulated for putting you in your rightful place

All@Sea said..
So let me get this clear, in NSW, if I were to swim to an anchored vessel and climb aboard via a tender tied alongside I could be fined, but if I haul myself up the anchor chain or onto the transom I'm In the clear?

How about if I were to (for arguments sake) swim to the boat towing my wife in a small tender without a PFD... would she be fined?

"If the law supposes that," said Mr. Bumble, squeezing his hat emphatically in both hands, "the law is a ass - a idiot. If that's the eye of the law, the law is a bachelor; and the worst I wish the law is, that his eye may be opened by experience - by experience." (en.wikiquote.org/wiki/Oliver_Twist)

Your wife will be fined because being by herself in a tender is obviously incredibly dangerous. You, swimming alongside, are doing something safe and normal so you'll be OK.