Here are a few suggestions for your next trip from Gdynia

In 4 hours, you can reach Varsavia, Posen.

In 5 hours, you can reach Łódź, Breslavia.

In 6 hours, you can reach Berlino, Cracovia.

In 8 hours, you can reach Ostrava.

In 9 hours, you can reach Amburgo, Brno.

In 10+ hours, you can reach Parigi, Budapest, Vienna, Stoccolma, Praga, Bruxelles, Amsterdam, Vilnius, Bratislava, Zurigo...