Ye I know I had that thought to begin with but then I would have to make a complete map so I decided to make it auto generated. So the truth is that I don't really know how far it is to the next umbrella. There is a 5% chance that it will spawn when a new ground tile is generated. I have some plans to add more any maybe a distance indicator to the next umbrella isn't such bad idea when I have time.
Thanks a lot for playing!