We found a better idea!!!!!!
In the harwear store look for thse picture hanging thingies. The look like velcro.
You stick both sides to the back of the picture and then onto the wall. The wall side sticks and then you can rip the velcro off to remove the picture.
The whole sticky velcro removes from the wall with a pull down tab when you have finished with it.
None of our photos have fallen off at sea
Mark