I was in the market for a lightweight, waterproof jacket to weather Florida's frequent summer showers, and had hoped this Portwest Rain jacket would do the trick.  It is definitely waterproof, being made from some fairly durable plastic material with the seams completely sealed.  The only problem is that with the exception of a small area in the upper back, it is unlined, which makes it very hot and sticky to wear.  There are elastic bands inside the sleeves, which do prevent water from getting in, but also prevent air flow.  They did put in a couple of small, grommeted air holes below the arm area, but it really does not help.  It also could have been cut a bit larger in the hips to allow for more comfort (and air flow).  The jacket is well put together, but the design could have been improved with a little effort.  Might be okay to use in cooler climates, but it won't be one of my favorites.