Bluebottle jellyfish have a gas-filled sac that floats on the surface and tentacles that hang underneath. They can change the orientation of their float and use it to 'sail' with the wind.
Free floating in open ocean.
Bluebottles often get washed onto local beaches, and should not be handled due to their poisonous sting. Species related to the bluebottle have killed people in the Northern Hemisphere although no deaths have been reported in the Southern Hemisphere.
Not a true jellyfish, actually is a colonial animal called a siphonophore.
NZ Coastal Marine Invertebrates