If you don't kick and you want your feet to be close to the surface you have to get the chest into the water. You must also finish the stroke which also lifts the legs. I have never used hand paddles, hand paddles are to help a person follow a correct path for the hands to follow underwater. If you are not following the correct path the paddles slide in all directions. Now do they build strength I really do not think that is the purpose of hand paddles.
If you don't kick and you want your feet to be close to the surface you have to get the chest into the water. You must also finish the stroke which also lifts the legs. I have never used hand paddles, hand paddles are to help a person follow a correct path for the hands to follow underwater. If you are not following the correct path the paddles slide in all directions. Now do they build strength I really do not think that is the purpose of hand paddles.