Icelands is a big left that works from 4-12 plus feet. It's best on lower tides and bigger south swells, which peak way out the back and then wind down the shelf. The peak can shift a bit, and suits tow-ins on bigger days, when the drop also gets sucky. There are rights off the peak on smaller days. Barrels are most commen on bigger swells and lower tides, often straight off the drop. On high tide it can be a bit fat.
General
It's a clean wave that's probably better when the swell is bigger, and has a bit more south in it. Not the best left in the Mentawais, but holds just about any size for adrenalin seekers.