This is what I use. The /cancelform is more strict, but I've also added the use of Dash when already in Cat Form.
#showtooltip
/cancelform [noform:2,swimming][noform:4,noswimming,outdoors][noform:3,noswimming,indoors]
/cast [swimming] Aquatic Form; [outdoors] Travel Form; [form:3] Dash; Cat Form