Hadn't considered the salinity issue,
but,
of course, the IOC have prepared the way,
with the Open/Sea swimming.
Pondering further, we could have a four-year relay of whales circumnavigating the oceans,
and,
delivering a (representative) Olympic Torch to the next venue.
Slippery slope.
Why only unattached horses?
Why not walrusses or manatees in the swimming pool?