The first time I realized that some people wanted to be mermaids is when I read a (probably deleted) Yahoo question that asked "How can I turn into a mermaid? Serious replies ONLY!" and included the fact that a water spell had not worked for the user. I hope she's reading this post, because now she (and you) can turn into a mermaid as much as you like thanks to a mermaid school in The Philippines.
The Philippines Mermaid Swimming Academy has been functioning since 2012 and specializes in teaching aspiring mermaids that flapping your fins can get you pretty far. And that it's actually good for your abs (which is why King Triton was so built).
The classes, which are held in rivers and lakes (that participants are used to) teach students how to swim like mermaids as well as how to care for a mermaid tale. Advanced classes teach Ariels of all ages how to scuba with a tail as well as hot to use a water scooter as a mermaid. And though it sounds like it would be expensive, a two-hour class only costs about $40 and comes with a picture. Totally worth it!