Swimming after rotator cuff surgery

I am 76 and have been a swimmer all my life. I have had full tears in both shoulders. My last surgery was 6 months ago. I am now swimming half an hour 3 times a week with no problem but use pulleys on arms for 3 minutes prior to entering pool. All good with crawl alternating with breast stoke but thumbs up for breast stroke to keep from reinjuring cuff.