Transcript for Inside big mermaid convention's fin-tastic weekend
Conventions are traditionally rather boring, staid affairs. People peddling new auto parts, insurance policies or caskets. Tonight, though, we'll take you to the mer-mania mermaid convention. Here's my "Nightline" coanchor juju Chang. ??? Reporter: No shirt, no shoes? No problem. Welcome to ncmer-mania 2017. Yep, this is a mermaid convention. Mer-folk, both amateurs and pros, diving in for a weekend of fun, flair, and fins. Being a mermaid means being the bridge of fantasy and reality. Reporter: From underwater posing workshops to offbeat modes of transportation. Here we go, back to the big pool. Reporter: These die-hards are making waves, wowing in tails that can cost up to $5,000. All brought together by a shared albeit unique hobby. It was Daryl Hannah who first made a splash. What are you doing, sweetheart? Taking a bath. Can I come in? No! Reporter: Then it was Ariel's turn as "The little mermaid." ??? Under the sea under the sea ??? Reporter: Now it's Hannah burgess who says for her it's about pushing fun and fantasy. These are one of my favorite part of my room. They are handmade by me jellyfish lanterns. Reporter: We met the 21-year-old art and design student at her college in Virginia. This is fish netting that I got to actually make tops with. Reporter: Although hours away from the ocean, she's found a way to bring the sea to her. Here is a jar of sand from the outer banks which I collected myself. This room is kind of my mermaid grotto. Reporter: Dubbed nova cyrene, the Virginia mermaid, Hannah teaches and performs nationwide, making a plan online with 20,000 Instagram followers. She's quick to acknowledge it's an uncommon gig. A lot of people really don't understand what I mean when I say I'm a mermaid. I know I'm a human but I just really enjoy dressing up as a mermaid and entertaining children, swimming in coral reefs, doing really special things that not a lot of people get to do. Reporter: On this day, Hannah is packing for the annual mermaid convention. And let's just say the dress code is very specific. This one was custom made for my measurements, and I picked the paint job, and all of that. So this one cost me $2,100. The starfish are made out of silicone too. It's very glamorous, has a lot of sparkly things on it. Reporter: She's set and ready for what promises to be a fantastic weekend. They say it's better under the sea. And these guys really mean it. Being under water is an extremely exhilarating feeling. Your adrenaline is pumping and you're kind of scared but also partly being relaxed and enjoying the fact that you're under water. Reporter: Here at one of the largest mermaid gatherings in the world we meet Chris, actor turned mer-man, who's been part of this community the past four years. I would call a professional mermaid a giver of dreams. Go get that dream. Go be you. Reporter: Chris says the big motivator for him is upping the image of men in the mer-folk industry. I want to create a world for them or at least help create a world for them where they don't have to be afraid. I was picked on in school for my love of the ocean. When I set out to be this character, I wanted to make it a safe haven for other men and just be a role model, be an inspiration for them, break down as many doors as I possibly could. It's just what I do. It's my job. It's the job that I've wanted to do. And I just keep -- to quote dory from "Finding Nemo," I just keep swimming. It's just an amazing feeling to know that I've made an impact on a lot of people in this business. And people that are looking to join the business. So it's wonderful. It's very overwhelming. Reporter: 300 participants from around the globe have traveled to this meetup to socialize, check out the latest gear. These are $3,000 silicone tails. Reporter: To attend seminars about all things mermaidy. Know what you're wearing and doing underwater. Reporter: Husband and wife Amanda and Joseph are coaching students how to strike a pose while submerged. Taking them from classroom to pool to test their moves. Hannah, the veteran, stunning in these underwater shots. I learned a whole lot about breath control, buoyancy, things like that. We had some good laughs while we looked at some of the candid photos. So it's been really fun. Reporter: Hannah says her mermaid obsession began as a child, like many here watching Ariel in action. ??? Up where they walk up where they run ??? ??? up where they stay all day in the sun ??? ??? wandering free wish I could be part of that world ??? When I was a child, I would actually put both of my legs inside one pant leg in my leggings when I was a kid and have diving flippers and I would go in hotel pools and public pools and the swim like that. Reporter: Now she's able to share her passion with other young kids growing up with a taste for fantasy. Who do you think you are, cried the rainbow fish? Reporter: While some might find it odd, Hannah says at its core the convention is about bonding with friends. Everyone who comes here has the same love for mermaids and the same love for the water. And we really understand each other and we understand the commitment and creativity that it takes to be a mermaid or merman. I've made so many friends I can truly say they are my best friends. Reporter: Friendships that go a little deeper, both above and below the surface. For "Nightline," I'm juju Chang in New York.
This transcript has been automatically generated and may not be 100% accurate.