Ferry Nacka to Gamla Stan

Ferry 83 runs between Nacka strand and Slussen (Gamla stan), map: https://images.ctfassets.net/9t2ujbulz1j7/5Y6CMB80mI56nSk0p4JWs1/2d4f9b8d3fc0fdeb53999e551c58e256/pendelbatslinje83-april2024.png

It's not the most frequent ferry though, but you can also use a combination of routes 80 and 82: https://images.ctfassets.net/9t2ujbulz1j7/54nrO8TFgmn9YKRcT0cMLU/ea5c6e0c4ff8f4e87fa69daeb8d9b24e/pendelbatslinje80-april2024.png

Yes. Ferry line 83 (pendelbåt linje 83) from Nacka Strand. Get off at the Slussen stop. Map is here:
https://images.ctfassets.net/9t2ujbulz1j7/5Y6CMB80mI56nSk0p4JWs1/2d4f9b8d3fc0fdeb53999e551c58e256/pendelbatslinje83-april2024.png

The timetable can be found on this page. Select ”båt” and then the PDF for line 83. Right now, they only have the time table for line 83 for the period of April 14 to April 29 so you will need to check back when the new timetable is posted.
https://sl.linjetidtabeller.se/

You could also take ferry line 80 from Nacka Strand to Nybroplan. This would be about a 10 to 15 minute walk to Gamla Stan.

Thanks. I appreciate the reply