A few years ago I saw a hammerhead shark attached to a sea turtle's rear while at Jimmy's Beach NSW. Assume it was trying to eat the sea turtle not introduce itself.
Had a very large sea turtle (5' across) surface just in front of me at Batemans Bay (South Coast NSW) which really scared the #### out of me. He took a breath and disappeared. Where I sail now, we have a smaller sea turtle that appears every so often, but he is a small one. They apparently eat the large jelly fish which have the tenticles hanging down; good by me.
Twenty years ago while at Glenelg Beach (SA) we were warned about the white pointer sharks, so while sailing a fair way off-shore I nearly had a coronory when a large white shape about 8'-9' long, appeared below me. I was ready to get the hell out of there, when it surfaced just in front of me. It was a very playful dolphin, just wanting to say hello. Phew!
At The Haven, Terrigal Beach I was sailing out as two small hammerheads were coming in. Were going to the boat ramp I'd say to get some off-cuts.
Once while sailing at Kyemah (is that how it's spelt?) in Sydney a fellow sailboarder hit a submerged car tyre. Ripped out his fin and broke his boom when he crashed. He got back in OK but it did take a time.
Very few naked girls though
!!!!
In the southern ocean sailing back to Perth from Melbourne I saw 2 water spouts about 20km off our bow. That was pretty cool, but as we went along a pod of +300 dolphins was exiting the immediate area. the Pod stretched over about 500m roughly given there wasn't much to judge distance by out there.
Moored my yacht off Garden Island. Had a nice party on the beach and came back to the boat, climbed the ladder at the back to find a big python coiled around the hand rail! Nearly had a hart attack b4 realizing was a python! was pitch dark!
I found Wilson!
Windsufing at Sanctuary Point (NSW) and came accross Wilson going his merry way.
Stopped, picked him up, though "how an I going to get this back to land", and decided to leave him to his own adventure.
Caught it on my Go Pro!
I'll upload the vid as proof but here's a pic from the video
It wasn't floating, but today at the lake in Canberra, where we launch in an easterly, there was a pair of Lace top stockings and a pair of black panties in the grass.
Disturbingly ... When I got back in to pack up the panties had gone !
found a floating plastic bag of 25 or so toy dolphins. i dragged them back to the beach and within minutes passers by were getting stuck into the bag and had taken them all
had a few :
dugong came up right in front of me, I nearly **** in my boardshorts thinking it was a shark 
was going full speed when I hit a turtle that had just surfaced, at first felt bad for the animal thinking I might have injured it, then cursed it when I saw my fin was gone and had to swim 1km to shore
wind had dropped so I was slowly sailing back towards the beach, spotted a large turtle, then a fin and then a shark ripping a fin off it.... kept my feet real close to the mast and started blowing in the sail...
through the years saw a few funny boards with footstraps, fins on each end and a handle in the middle, drifting along, couldn't be bothered, they looked too small.....
Haven't seen much not already mentioned. Sailing at Hervey Bay I saw a straw hat floating around so sailed over to it and just as I went to grab it saw a tiny baby stingray under it. Had a turtle surface near me in Mackay, had a small fish jump out of the water and hit my leg there too, and a few bounce off the deck. Rigging up maybe 20 years ago in Adelaide saw a water spout out to sea. Plenty of dolphins but thankfully never a shart. Last weekend at Mandurah a Shag surfaced about 2m in front of me, glad he chose the opposite direction to me. He must have fairly shat himself, I looked back after passing and he was doing circles on the surface, still trying to decide which way to fly
