Here's my recollection on finding it.
It was an early morning dive for me. If I got up early enough, I could swim out from shore, swim back, clean up and still make it to work on time. My pre-dive plan was to swim way out away from shore because the shallow area was already getting a little picked over. When I sank down, my depth gauge showed twelve feet. I wanted to be deeper. I could surface and swim out without wasting bottom time but I thought that I was pretty close to a drop off. I set a compass heading for deeper water and kicked fast and hard in that direction. I was even using my hands to propel me along by pushing off the bottom as I went. Without realizing it or grabbing at anything, there was an object in my hand from pushing off. It was likely a rock, but I looked at it. I could see that it was a bottle, a really early bottle. I surfaced and stared at it. I couldn't believe that I had found my first mineral water or what I called a blob soda. I had no idea I was in an area where it could be found. Plus, I wasn't even really searching yet. It was just in my hand without me knowing it. Amazing! After I stowed it, I was going to return to my original dive plan. Then I realized, I couldn't possibly find a better area. I searched in widening circles finding a few more bottles, but nothing within 30 years of the manufacture of this bottle.
Some notes about this.
The bottle was not listed in my main guide to Wisconsin bottles by Roger Peters. That made me think it could be unknown. It turns out to be known but it is also fairly rare. A lucky find, no doubt about it. You don't often get a rare variant on your first find of a bottle type.
I still have not found many of these early sodas. They just don't turn up (for me at least). I have only found one other. The little circle at the bottom is my hutch soda count. When I find a whole one, I keep a running tab at the bottom by year. I never find anywhere near 55 a year anymore.
My recollections on finding this bottle.
I wasn't finding much and decided to cover some ground. Swimming along, I bumped the bottle. I was confused by the feel of that blob but quickly realized that it was a clay. This thing looks so prehistoric.
Thanks so much Sandchip. Very nice comments. I'm really glad that I kept up the log as it is fun to reminisce and read details that I had forgotten. I do have more stories to tell when I get around to it here.