Very long time ago, back in the day, when you use to sail to the west side of 'Eua island from the east of Tongatapu, you would see Eua island in the far distance.
As you are paddling towards Eua Is, you would see a large group of TOA TREES on 'Eua.
This group of trees to the naked eye looked like a allot of trees but as you get closer to Eua Is the group of trees that you sighted earlier is actually only 3 trees. 3 gigantic Toa trees.
The sighting of this group of Toa trees from sea was actually used as a indication of distance and time of how far you are away from 'Eua Island.
FOTU LOI means lie or deceive.