Spearfishing Float - Looks like a lifeguard float? That's because it basically is! This is the type of float originally started with years ago and they are making A huge comeback because they are just a great design that is hard to improve.
No need to pay a bunch of money for something that really doesn't do as good a job as this will.
They are made of a super durable, UV resistant, hard plastic. They even have a port that you could remove to fill with foam in order to make into a solid float.
They come with nylon line and safety handles that you can hold onto for a rest and make carrying much easier.