Hi-- I've been using FemSeven for over 3 years-initially the Sequi and now Conti. I very quickly realised that they need "help" in sticking and I have always kept them on with a Tegaderm dressing- this is a transparent dressing which sticks over the whole patch. The important thing is that you must apply the Tegaderm immediately after applying the patch -in this way the patch (with its hormone-containing adhesive) will remain adhered to the skin. If youwait until the patch adhesive has failed and try to stick the patch on with tape, the hormone/adhesive patch coating will no longer be in tight contact with the skin, so it won't work.
All the other usual tips still apply- dry warm skin, no moisturiser.
I find the most secure place is on my belly! --also you need to be able to see what you're doing with the Tegaderm so buttocks hopeless!
This method should still keep the patch secure when swimming.
Re keeping patch on for longer than a week- I think the hormones will have run out after a week so I think you should apply a new patch after a week .
Good luck!
ps cheapest Tegaderm I found were on Amazon , the size you need is 6cmx7cm "Tegaderm Film Transparent Film Dressing Frame Style" --