Summary: Maybe more of a 3.5. A fun, free experience, but is hit and miss, so don't expect enough of the water to be warm enough to swim comfortably. Details: It's a fun experience to feel the hot water seeping through the sand beneath your feet in random places (you have to hunt for it some times) - it's quite a surprise at first. But be careful - in some places (or if your feet dig in too deep) it was too hot to the point of painful (probably not damaging, but certainly uncomfortable). And unfortunately, even when we went in mid summer (after a rainy week), most of the water was still uncomfortably cold, especially past your knees or waist. Some summer days will be better I'm sure, but many cooler months will not. We even tried digging a hole in a hot patch and walling off too much cold water (too hot to dig with your bare hands) - it got quite warm, but occasionally a scalding hot current came through the sand that made me jump. Oh, and no facilities or signage, so go prepared.