Garden Spider from Hawaii

Argiope Genus?
Greetings!
I just returned from a Hawaiian vacation and found this large spider with beautiful markings (palm-sized, including legs) hanging out in Kauai. An internet search quickly brought me to your site, where I learned that I had probably found a spider in the genus Argiope. I thought that it was perhaps the spider that goes by many names (Orb Weaver, Writer Spider, etc.), but its body is slightly different from those pictured on your site. I then came across the picture taken by "Nick Hobgood," which you dated as 02/26/2006. That spider looks nearly identical to the one that I came across. Here is his picture, followed by mine: And here is the spider that I found: Can you confirm its identification, and can you tell me about that zig-zaggy line that runs through this and other similar spiders’ webs? There were quite a few within the vicinity, and they all had that feature in their webs. Thanks for your expertise!
Becca

Hi Becca,
This is Argiope appensa, commonly called the Garden Spider, though that common name is shared with numerous other species.