The aliens keep themselves aloft by means of dangling onion-like buoyancy bags
, and communicate with pulses of light.
She said that they used their rucksacks as buoyancy bags
but quickly found themselves waist-high in water and forced to swim.
Finally, unless they're fully kitted out with fitted buoyancy bags
, canoes aren't really appropriate for big white water (although smaller rapids can be negotiated given the appropriate combination of courage and skill).
They were washed against a battered life-raft and held on to the buoyancy bags
on the side.
But it has been done now and buoyancy bags
have been fitted.
I helped carry buoyancy bags
and inflating equipment to stop the 14ft creature being battered to death against rocks by the swell.