Pontoon Sun Shade
It seems that most pontoon boats have either a hardtop or a movable, bimini top. Some people call them pontoon boat sun shades. (Others don't.) There are also T-shaped tops. That allow fisherman the ability to cast from more locations on the boat, but those provide the same complications at boat storage time as hardtops.
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Since you'll be out in the sun, and shade will only be near shore, you probably do want some type of top or boat sun shade, or sun cover.
Again, it comes back to usage.
How do you plan to use the boat? If you want to be shaded most of the time and you don't mind restricting your fishing technique and you don't mind storing a tall vessel, then a hard top is probably what you'll end up with.
However, a bimini top can give you almost as much sun shade coverage, it is more easily removable for storage, and it (similar to a convertible car) can be raised and lowered when you want it to be shady or sunny. (Or when you want to cast that line a little further from your favorite position on the deck.)
Some pontoon boats also have fixed or temporary changing rooms. The materials can hang down from the bimini or hard top to form a small changing room for privacy during changing into/out of swimming attire. Some pontoon boaters will also use such a 'privacy partition' to hide a portable commode.
The next time your out on the lakes where you plan on taking your new pontoon boat, take note of the pontoon boat tops that others have. Pay attention to the leisure activities they're using the boat for, and if it's the same types of activities you'll be doing pay extra attention to the type of top they have. Do they have a boat sun shade that you'd want on your pontoon boat?
You'll soon see a trend that boaters that are like you, will answer the question for you by the type of top they have - and you can tell from a hundred yards away. Then you'll have it "made in the sun shade" (not just made in the shade)!