I am a 31 year old male. 130 lbs. Have a slight hunch back.

In the apartment community where I live there are two swimming pools. I bought a swimming trunk and I have been trying to teach myself to swim for the last 2 weeks now. I made a lot of progress.

I am able to float on my belly. I am able completely submerge myself underwater and swim for 10 to 12 feet. However the thing I am struggling with is keeping my legs from sinking if I bring my head out of the water. I don't know if it is because I am in a shallow pool(4.5 feet to 3.5 feet) or something.

I cannot swim for longer distances with my head completely submerged under the water.

Do you folk think that buying a kick board will help me get to a point where I am able to stay horizontal in the water while I have my head sticking out of the water?