Why you should bring you GF to swimming before getting married ?
Actually there are 3 main points that would have you feel better.
1. You could see all her body shape.
2. You can see clear her face without making up.
3. You can know that is she have swimming skill or not. If no, make sure you teach her swim. TO PREVENT she ask in the future for this question, If me and my brother dropped into the water, who will you help first ?