just a quick look on google I got 2 shipping companies who operate from Taiwan, the contact info is on the page.
just drop them an email and ask if they have passengers on their ships and if so how to book passage.
http://www.cmt.tw/air-agency-and-tourism
https://www.evermorenet.com/webls-en-us/contact/contact.html
also the government website for the ports which shows the port fee for passengers on commercial ports, which is normally a sign its a regular thing.
Article 5
Passenger port dues are collected from passengers for each departure by the tariff rate of forty New Taiwan Dollars (NT$ 40).
If you want it, do some leg work and make it happen.