Unable to create DigitalOcean droplet with docker-machine create without explicit image

It seems the example and used in the tutorial for creating a droplet below doesn’t seem to work.

docker-machine create --driver digitalocean --digitalocean-access-token xxxxxx host1.

it looks like I have to specify an available image at DigitalOcean that the Droplet will be based on. But there isn’t a list there to choose from. The failure of the above seems to point to the lack of default image to base on. Is this correct?

Finally I was able to create one with the following command as suggested here

docker-machine create --driver digitalocean --digitalocean-access-token xxxxx --digitalocean-image docker docker-sandbox1

But despite previous failures, quite a few bad hosts has been reserved where the commands were issued. When I tried to remove these zombie hosts, but I keep getting the error: Error removing host “digital-sandbox”: unexpected EOF.