Good luck with this but it seems a bit contrived since you will be spending more time doing land travel than sea travel and visiting many more countries by land than water. In our circumnavigation we went to about 40 countries and territories and we stopped pretty much everywhere there was to stop - we might have added another ten at most. By your count that leaves about 150 to be visited by land transport or airplane. Sailing around the world is fine but there is more than one possible route and you are much controlled by the seasons - tropical storms in several areas along with the monsoons in the Indian Ocean and South China Sea.