The Celtic Siren

Swim as your whole self.

The version of me on stage and in the water: Irish to the bone, with a druid's quiet and a tail made for me alone.

Colleen as a mermaid on the beach, red and teal tail raised behind them in the waves

Colleen McCartney

The Siren is still taking shape. For now you'll find me in the water and on Instagram.

Colleen as a professional mermaid underwater

Everyone belongs in the water.

Metro MerFolk is the DC-area mermaid pod I co-founded around 2017. Any body, any gender, any age, tail or no tail yet. Come as you are, leave with your pod.

We swim safely: never alone, and with lifeguard-certified instructors for any teaching.

My mermaid story

Since 2017, Metro MerFolk has grown into a mermaid fitness and swim school for kids and adults around Washington, DC, with 1,400 members. It's a place where neurodivergent and LGBTQIA+ swimmers feel they belong in the water.

I also co-founded MerMagic Con. The first one, in February 2019, brought about 500 people to Manassas, Virginia, and was billed as the world's largest mermaid convention.

The Washington Post has featured our mermaid workouts, and in 2025 it named me as the Celtic Siren behind Metro MerFolk.

Colleen in a mermaid tail, photo 1
Colleen in a mermaid tail, photo 2
Colleen in a mermaid tail, photo 3
Colleen in a mermaid tail, photo 4
Colleen in a mermaid tail, photo 5
Colleen in a mermaid tail, photo 6

Let's connect

Come say hi

I'm on Instagram as @TotallyColleen for the whole colorful life, and on LinkedIn for the business side.
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One person, every door. Founder at Nerdly, former professional mermaid, and builder of systems that fit people. · Instagram · LinkedIn · Privacy Policy · Terms of Use