I noted 2 of these markers deep in Braun Bay. I think they may be the markers delineating the Fish and Game property lines even though the "rules" call for them to be orange balls. I'm not sure what the bottle is marking.
Attachment 1158349938
Then there are a few orange (some faded orange) balls in the Braun Bay No Rafting Zone. They could be the "mooring balls" that Marine patrol is supposed to set out to delineate the 75 feet from shore anchoring area. I think they look like Loon Nest area markers. Maybe they indicate anchors for the water volley ball net.
Attachment 1158349981
Thanks for your excellent chart/map.