I’m looking for a printer to print from my iPad. I live on my boat and do not have WiFi. I connect using data roaming. Is it possible to connect a wireless printer?

iPad natively supports AirPrint - which requires a WiFi network. There are many cheap WiFi Routers that you might use to create a local WiFi network for both your iPad and [AirPrint enabled] Printer.

You might also consider a Cellular Router (commonly known as MiFi) - which can provide broadband internet connectivity via a Cellular network; its WiFi hotspot can be used for your iPad and Wireless printer.