Strange Trimaran in Madang, PNG

I've had the pleasure of being able to go out with one of my buddies here in Madang, fishing on his motorboat. Went out Friday afternoon and saw this boat out there. I didn't have my camera with me so couldn't take any pictures of it. Went out fishing again today and brought my camera. I've never really seen anything like this. Not that I'm mister experience when it comes to anything on the sea. In fact, quite the opposite. Maybe this kind of thing is really common and I'm just too ignorant to have ever noticed. What is it?

It has two amas. The amas are made of bamboo lashed together. It looks as if there is actually a lower ama (see picture) and an upper ama. The lower one looks like just a single piece of bamboo maybe. It's suspended below the much beefier main ama. I would guess that this is so that the main ama isn't always creating so much drag in the water; the lower, simpler ama giving just a touch of stability to the ship until it needs more. Not sure though. Note too the curvature of the ama. Though not as easily visible on the other side, they both have about the same curvature built in.

Then on the iakos (they're huge!) are stored a bunch of these little wooden boats. Even these little wooden boats are a style that looks different than anything I've ever seen before.

This boat just sticks out as different... and it's an outrigger (though not a sailing boat) and so I thought I'd post some pix here and see if anyone has ever seen or knows about anything like this? What is the purpose of this boat with all it's little boats?

The other picture was just a nice shot I got of some kids out on the family dugout.

Just a few more days until we go back into the bush. We've been out way too long. As well as looking forward to seeing my friends and talking about some exciting things regarding the church in Mibu, I'm looking forward to getting some little bits of time here and there to work on Shan Skailyn.