There seems to be a lot of things to do in Shikoku in nature. If you like climbing mountains, or camping, or fishing, or hiking, or surfing, or swimming, Shikoku is a kind of naturalist paradise. But there are also outdoor activities that are available to people who are not so interested in working hard or hiking hard too. There are places to relax and unwind. There are beaches. And there are a number of on-the-water activities to enjoy too.
Today I want to highlight one such experience and that is the glass bottomed boats you can enjoy in Kochi. Tatsukushi Kaichu Kanko, located in Tosashimizu-shi is the place to connect with for your calm and soothing cruise over the water. They take you through coral reef areas so you can see into the water and the natural habitat of water creatures. Something to consider if you have come to Shikoku to get away from the stresses of the world, and to easily submerse yourself in the Deep culture of Japan.
The link is here: https://hata-kochi.jp/en/experience1499071697.html