Regarding the additional requirements, yes I am aware of them. My son belongs to a swim club and attends the practices regularly, they have "dry land" and talk about the safety and the do other excercises to build strength and stamina.
Regarding the "No", I appreciate and respect your answer, but...can you show me where it specifically states that a Cub (Webelos in my sons case) cannot earn it or does not qualify, and that it is only a Boy Scout or Venture patch?
Over the years, I have heard many "no you cannot do that's", only to realize later that it was their old council rules, or their opinion, or the way they thought they read the G2SS or other document and needless to say, an activity was cancelled or a patch was denied only to find out later it was an opinion, and not factual.
By the way, I am not looking to score another patch for my son. It was a leader from a different troop who was watching my son swim who suggested this and even offered to sign off any application of form needed. Also, I thought of this in the past, and asked the very same question and was told no...I accepted it as gospel...but when I asked to see it in writing, they said they would get back to me and needless to say I waited and it fell between the cracks and I let it go, and I never heard from them and they never supplied the backup to their "NO".