To be surface rescue swimmer...You do not even have to know how to swim.
...i remember a former attc instructor friend of mine would motivate students by asking them if they'd prefer to jump from a helicopter or be a "dope on a rope"...
Unless your already in the CG I don't recommend looking to hard at the AST rate, especially if you have just finished watching the Guardian, you want glory? Swab my deck!
And in reference to your question, the aviation rate has very stringent physical requirements, especially with eyes...no colorblindness allowed. Try taking your aviation questions to the airdale forums...good luck shippy.