What is it??

The tide was fully out so this Wednesday's walk with the lads had to be a beach walk along the beach, round the spit and back via the estuary.
On the mud flats of the estuary on the latter half of the walk we came across a number of very large jellyfish - some were 70-80cms diameter, possibly larger.
We weren't sure if they were dead or simply awaiting the incoming tide to float off and away. I suspect the former.

Graeme did some investigating on internet and thinks they might be Cyanea capillata, the Lion's Mane jellyfish - the largest known species. They are found in colder waters of the Arctic region but a related species is also found in Australia and New Zealand. Apparently these can grow up to 2 metres in size! Impressive.
This reminds me of a weekend with a group of Kiwis on Jana Island in the Arabian Gulf (between Saudi Arabia and Iran). We were on Jane island to observe the green turtles laying their eggs - we weren't disappointed. On the Sunday morning the temperature at sunrise was well over 40 degrees - the only sensible option was to go snorkelling off the boat. I was on my own only about 40-50 metres from the boat when I was almost enveloped by what seemed a huge jellyfish - it was almost translucent. I felt I could have put my hand out to touch it - rather the opposite and I struggled back to clamber up to the safety of the boat deck. At the time I was thinking of the Portuguese Man o' War, but could it have been one of these Lion Mane jellyfish. I guess I will never know. I'm not a strong swimmer and that was the last swim I had that day. I gather the sting from these creatures is best avoided!!