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  • Writer's pictureEarl Sullivan

Every season is a new season...

Thoughts on when to come to Asu Island, West Nias, North Sumatra, Indonesia

The most common question that I get from people researching a trip to Asu is, ‘When is the best time to come?’

The answer that I invariably give is, ‘Any time between March and October and for as long as you possibly can pull from your work, life, wife, etc.’ March through October is our surf season, and as we say out here, ‘anything can happen’. There’s a reason we say that, and it’s the same reason that makes this zone is the most consistent surf zone in the world and your best bet for a surf trip, and here’s why (or just click here to skip down to the real nitty gritty of the answer):

Asu lsland sits less than 1 degree north of the equator, which puts us smack dab in the doldrums. Never heard of the doldrums? Well, the doldrums are well known to most sailors around the world as the Inter-Tropical Convergence Zone (the ITCZ, or ‘the itch’), which is a belt around the Earth extending approximately five degrees north and south of the equator. Intense solar heating near the equator forces moist air up into the atmosphere, some of this warm air cools, falling back down to the earth in the form of rain showers, essential for cooling down nature’s warmest bathtub to the comfortable 30 degree C (or 86 degrees F) water that we can surf in all day, no rubber insulation required. In the doldrums, because the air circulates in an upward direction, there is often little surface wind in this band, which is why sailors know that this area can becalm sailing ships for weeks and why surfers come in droves for the cleanest ocean conditions on the planet (

Thus, a surfer’s dream is born, the island nation of Indonesia. 18,000 islands that sit at the far edge of a massive fetch of very active ocean. Ever heard of the Roaring Forties? Well, some of that moist warm air that rises vertically at the equator falls back down in tropical rains, but most of it heads south, or north, and descends back to the surface of the earth at around 30 degrees south, or north latitude, nature’s process of reducing the temperature difference between the equator and the poles created by uneven heating from the sun. ( Here the air is deflected toward the poles by the Earth’s rotation, causing strong prevailing westerly winds at approximately 40 degrees, the source of the famous trade-winds. This is all good news for sailors, but even more attractive to us as surfers is something a little lower down, affectionately known to big wave lovers as the Furious Fifties and yet lower down, the Screaming Sixties, cause, well who doesn’t love a screamer? These lower latitudes are where the biggest swells are generated from, with the greatest fetch and longest periods of wave frequency, which is the source of the real power of the waves that go peeling along our local reefs.

Another special consideration that puts Indonesia at the top of the list for surf travel is the way the southern hemisphere is so strategically structured, part 2 of the surfer’s dream. There are no major landmasses that obstruct the circulation of this fantastic swirl of energy dancing its way around the Earth between 40 and 60 degrees south latitude. The storms born in the South Atlantic Ocean, for example, flow below the tip of Africa into the Indian Ocean where they keep the swell party rolling along under Australia and then right into the South Pacific Ocean where they bloom again before being compressed under the tip of South America, finding their way full circle back to where they started in the Atlantic. This is literally an around-the-world, raging, swell-spewing party to which every surfer is invited.

Storms that flow east from the Atlantic, begin blooming under the tip of South Africa conjuring up 25 second period southwest ground swells that smash into Indonesia with tremendous force, generating swell for days on end. This storm energy often reforms again on the eastern side of the Indian Ocean sending another pulse of southern energy on its way out of the Indonesian swell window. These are the events that create the 2 week trips of our dreams with back to back swells in the overhead to triple overhead range, a non-stop, surf ‘til you drop, marathon surf trip.

So, back to our original query. When is the best time to come to Asu? Well, if you’re looking for head high to overhead waves with very few people around, then your best bet is March or October. If you want to make sure you have a chance at getting a bit more juice and seeing something in the double overhead range, then look more toward April-May or September. If you’re looking for the real juice, then historically speaking, look no further than June-August when the southern hemisphere winter is in full force and the screaming 60’s are, well, screaming for ya.

But, as most surfers can attest, there are no guarantees on a surf trip, we are all merely slaves to Mother Nature and her unpredictable whims. So, when planning your trip to Indo, be sure to allow as much time as possible to receive all the glory that your trip may be blessed with. A standard moon cycle from full to new moon (or vice versa) is 14 days, so in all seriousness, this should be your minimum journey, anything less is just a Hail Mary. Three weeks is better, but a month, if you can pull it, is the best way to see your favorite surf zone go through all its moods.

I know, easier said than done, but taking a month off of work just might be the best thing you ever did for yourself. I did that…14 years ago…and I’m still smiling.

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