I was asked to comment on my rhetorical question related to assumption of the risk as suggested by the photo I posted below. So here it is...
The question is whether a defendant could claim assumption of the risk based on the statement included in the sign. My answer is that the sign itself does not support the argument, but the argument can be made regardless of the sign. In other words, the sign itself may help the defendant, but only if the defendant can prove the plaintiff read it. Otherwise, the sign is pretty much irrelevant.
The message in the sign does not constitute a form of "express" assumption of the risk, because the sign, by itself, does not create an agreement between the parties.
Moreover, to support an argument of "implied" assumption of the risk, the defendant would have to show that the plaintiff knew of the risk, appreciated its magnitude and voluntarily decided to take the risk anyway. A defendant may very well be able to support that argument, but the support would not necessarily come from the sign itself. In fact, the defendant could make this argument even if there was no sign at all.
So why put the sign up if it sounds like it is almost irrelevant? Well, there are a couple of reasons. First, the sign really is just what it says at the top: a warning. And if the defendant can show the plaintiff read the warning, the defendant can support the argument for implied assumption of the risk. Second, the sign may discourage people from suing by suggesting that they don't have a right to do so.
Having said all that, it should be noted that many jurisdictions don't recognize assumption of the risk as a separate defense anymore.