I always use a mattress protector anyway but over here when I used to do aged care nursing we used these things called "Kylies" they're like a square of material quilted like a thick mattress protector maybe double thickness.... And I have seen lots of leaks not pass them so I think I'm just gonna double mattress protector and then sheet and by the time I hopefully would feel the gush and grab the sheets off it should be fine... I'm quite paranoid as I love my mattress and we paid a bomb for it and I dunno if I would find one the same so I don't wanna ruin it