So what your saying is don’t put an underwater sleeve in for an umbrella on the sun deck...
I've never had an umbrella sleeve, so I can't speak from experience, just a sort of logic. It's a hole, number one, that will collect dirt and possibly algae. Many people have them, and PBs keep installing them, so there must be a good way to take care of them, but not for me. They're also a penetration through the plaster that has a long pole (fulcrum) sticking out of it with a large wind sail at its end! It's the plaster that makes a pool waterproof, not the gunite underneath, so how does a pole in a hole though the plaster, which is constantly being forced back and forth by the wind, not eventually fail? Again, these must work, or they'd stop installing them, but it just looks like too much potential trouble to me. All this would apply to a lesser extent to a hole for a stair rail. I don't know, ask around about it. Maybe start a thread here and see if umbrella sleeve owners are having any problems or not. They must have to close them after each use, or maybe take them out of the pool when it's windy? I would have to where I live.
For me, I need some shade over the water. I solved that with a shade sail. No pole to walk around. Nothing in the pool. No cantilevered monster chunk of concrete counter-weight sitting on the deck. 100% wind proof. And for my yard, it obscures my view of the sky and surrounding area way less than an umbrella would. I never have to think about it or put it up or take it down, etc.
So... because shade and hand rails are available that don't require a penetration underwater, that'd be the way I'd go.
Oh, and for the sun deck? Have you ever had much success hiding from the sun under an umbrella? One that is in a fixed location? Even if you could fit your body under it, you'd only get good coverage for an hour or so a day! How are you and your significant other supposed to get comfortable under an umbrella, together? More umbrellas? I see people have them, I just don't get how they would work all that well. But then again, I'm not a fan of the sun shelf to begin with, so you'll need to gather opinions from others that have both, umbrellas and shelves...
Isn’t everyone’s first step the deepest since you come off the coping and into the water. Otherwise to maintain 6” off the coping the first step would only be 2-3” underwater which would be tough to light, clean and keep clean. Then the measurements from there would be odd water depth (3, 9, 15, 21, 27, 33, etc.) making it hard to get subs to get it right.
Plus the ledge depth is 9 or 12” deep and the consensus on these ledges seems to be most used and enjoyed between 10-12”.
I think very few pool steps adhere to the dimensions I described, if any. I think they end up being a compromise because of the reasons you point out. I don't think tripping on steps in a pool is a big issue. People seem to manage them just fine, regardless of their various heights relative to each other and the deck. That's why the steps usually include some sort of contrasting marker, so people can see them and navigate them. We don't expect pool steps to be even, like we do other stairways, so we take better care on them and watch where we're going. I was just pointing it out as something to consider, so that maybe you could minimize the height differences as much as possible. I don't think you're going to end up with a perfect solution, but I don't think it's going to be that big of a deal, either.
