Jeff Jensen has an interesting theory that it is Jack etc shooting at Sawyer's boat. So it would be sometime in 2008 when they get back to the island.
No idea if it is true or not.
Before reading Jeff Jensen (or our equally brilliant Creflo), I had thought the same thing. The Others were building a runway on the smaller Island, & these outriggers are similar to those used by Alex & Karl. So in (very late) response to LB's original question- I think that they did make future jumps.
what if that rope sticking out of the ground is the reason why the well is built in first place.
Cool idea. Very possible.