HI Vendetta,
It sounds like you are using the once-a-week patches, which are, as you say, annoyingly big. Have your doctor change to your prescription to twice-a-week patches which are significantly smaller. They also result in less skin irritation since they are only in one place for three or four days instead of seven.
The flank of my buttocks was where I usually placed them. Anywhere on your rear end that won't rub off will do, and will give better absorption than if placed on your abdomen.
I was on Mylan patches for many months, and even using two twice-a-week patches, my blood estradiol levels never got much above 50-60 pg/mL. As Liz pointed out, absorption cane quite variable from person to person. Getting them wet will not necessarily "ruin" them, other than preventing good contact with the skin. Estradiol is more lipid soluble than water soluble.
Hope that helps,
Terri