I learned to swim from a friend who could. In turn, I helped another to learn. All at a public (cheap) pool.
Do it the old fashioned way: row out to the middle of the lake and toss them overboard - if they can get out of the gunny sack the swimming part will come naturally.
Disclaimer That was light-hearted sarcasm and in now way intended to be racist. Old fashioned applies to whites as well as other ethnicity. If you or your loved one's are offended seek professional help immediately, it could be symptoms associated with thin skin, a common condition associated with lose undergarments in a bunch. If humorless conditions persists it could signal the onslaught of seriousness. Seriousness is a serious condition with side effects of joylessness and constipation. See your doctor.