Last Sunday I travelled by train to Wejherowo and the trip started here. There is a railway service in Trójmiasto similar to German S-Bahn or metro-like railway but not underground. The ticket fare (Sopot-Wejherowo) is less than 2 EUR and the ticket for bicycle is free.
From Wejherowo I cycled along 218 road toward Krokowa but halfway turned left to Tyłowo. I proceeded along Żarnowieckie lake via Kartoszyno and Lubkowo to Żarnowiec. In Kartoszyno a nuclear power plant was planned to be build but the project was abandoned. There are remains of the buildings of the plant erected (not particularly interesting in my opinion and the access to them is forbidden). Lubkowo and the nearby area on Żarnowieckie lake shore is a resort. There are hundreds of vacation homes built here---so many that an access to lake's shore is seriously limited:-( There is an old cisterian cloister and a church in Żarnowiec.
From Żarnowiec I proceeded along 213 road via Krokowa (There is a von Krokow family castle here but I did not visit it.) to Celbowo. BTW in a small village Zdrada one can turn to Mechowo to see Caves in Mechowo---a geological curiosity. Next I cycled a few kilometers along 216 road. In weekends usually there is a heavy traffic here as many people are trying to get to/from popular beach resorts Władysławowo, Jastarnia etc...
Finally I turned left to local road heading to Żelistrzewo (Don't try to pronounce this name :-) and approached Gdynia from the west, cycling via Mrzezino and Pierwoszyno. Again in weekends some clever people are trying to avoid traffic on 216 road and drive to Gdynia this way. Off season and during week days the roads here are rather empty...
The weather was fine, the traffic on the average was light. The road quality was fine as well without potholes etc... The total distance covered was 110 kms.
A KML track (with photos) is here: