One of them could be: Elephants.
Please mark your chart with our present position:
5 degree 38.5N
118 degree 21.4E
We had dropped the anchor here as we had seen some elephants ashore!
And then, last night at 3 am, a bunch of elephants swam across the river about 50 meters right in front of us.
It was easy for them to get into the water but at the other side the river bank was a bit steep.
More than an hour of struggling, huffing and hooting kept us awake. An awesome experience.
Mind you, we are NOT complaining: That's why we are here.
But, what would be the newspaper headline if we had been hit by one of them?