The Well of Transformation is a well of special water on the planet of the Tlalakans that dissolves the body of whomever enters it, leaving only the spirit/soul, which then forms a new body of whatever sort their heart desires. The Tlalakans use it to change into merpeople so that they can secretly use the waterways for their rebellion against Deceptitran. Any drone that enters the pool, being a soulless machine, is immediately dissolved to nothing as if by acid, but Transformers can use it safely. It seems to repel normal water, because its effects don't spread through the seaways.
The Transformers cartoon
Arriving in response to a distress call, the Autobots Bumblebee, Perceptor, Cosmos and Seaspray quickly got involved with the local revolution, with Seaspray just as quickly falling head over heels for Alana, one of the human leaders of the rebellion. Thanks to the miraculous Well, both Seaspray and Alana were able to experience life in the other's shoes, with him temporarily becoming a human with robot feet and her changing into a pink hued robot capable of transforming into a gondola, before realizing their love endured no matter their form.