Temporary grandstands are in the general area though, a bunker is not so your relief options are different.  I don't really understand what is so difficult about this.  You should be more upset with whoever organizes/runs your league for not implementing GUR, not the rule itself. Especially since this is a league and if it's at the same course every time it's likely that this isn't the first time the bunker has filled up completely with water.

Not sure if this is best to post here or start a new thread but I'm curious which stats you pay most attention to/how you utilize Shot Scope's data/charts to drive your improvement/practice?   I have 81 holes in Shot Scope now so starting to get a decent sample size of data about my game. I can obviously see the strokes gained numbers but I'm not quite sure where to go from there in terms of how to assess what specifically I need to work on.  Obviously it's approaches and short game for me, but when I go into those tabs on the left for those specific areas, I'm not quite sure how to use the information to make it actionable in my practice.   

I guess we’re kind of getting into semantics here, but you state “trading a bunker lie for a grass lie”. I would argue that a bunker under water is no longer a bunker. It is basically a small pond where there isn’t supposed to be one. The course has an unplayable condition due to weather and poor maintenance. Hitting a ball out of three inches of water is not a realistic option any more than hitting through a temporary grandstand is. Just my opinion.

So here’s the thing, you’ve treated the bunker as if it were GUR, which would actually be the appropriate course of action except you and your playing partners are not authorized to determine that for yourselves. The Committee in this case would be the golf course and in an ideal world, they would have handled their responsibilities and told you at the beginning of the round that X bunkers are under water, treat them as GUR. I’m actually ok with how you handled the situation in a casual round TBH but this is the rules forum and you asked about a rules clarification so there’s a specific procedure for that. As for your proposed rule, I don’t agree with the logic at all for the reason I outlined in my previous post. You are trading a bunker lie for a lie in grass for no penalty. And also, there are already rules in place that address the exact situation you found yourself in, including relief options for if the bunker was appropriately marked as GUR or not.

Someone asked would pros accept someone else keeping score. It’s done in every other sport. That’s what scorekeepers are for. It’s an antiquated rule. It’s fine for non-professionals.  I feel like there is a lot of resistance to rule in golf, as if these rules were brought down on stone tablets by Moses.