Not sure if there are many here on TF cruising in the Baltic region. For those few the following might be helpful if you intend to pass the bridges in Szczecin / Poland to connect the Baltic Sea and the inland waters via the river Odra.
Basically you have two choices in Szczecin, the Eastern and the Western Odra. You can easily change between them outside and inland, on both ways you will have to pass very low bridges.
Eastern Odra: A railway bridge, clearance 3 m (9' 10"). You can reach the bridge via VHF to request to open it (clearance opened is 6 m).
However communication might be very difficult depending on bridge personnels ability to understand your language - of course a no brainer if you are fluent in Polish. Our experience - not speaking Polish - are waiting times between 5 minutes and 5 hours, so it can be a PITA.
Western Odra: Two fixed bridges, clearance 3.4 m (11' 2"). However with the help of a Polish friend we were able to figure out the gauge level to which this clearance is related too: 590 cm at "Most Dugli".
Under O?rodek Koordynacyjno-Informacyjny Ochrony Przeciwpowodziowej ? RZGW Szczecin
you will find the actual gauge:
row "Szczecin - Most Dugli", column "Stan" gives the gauge in cm.
Today's reading is e.g. 508 cm. Therefore today's bridge clearance is
340 cm + 590 cm - 508 cm = 422 cm = 4.22 m (13' 10").
Knowing this we pass nowadays Szczecin in a reliable time without waiting for bridge opening via Western Odra if calculation above gives a reasonable margin (gauge reading is actualized only once per day and might be negatively influenced by strong northern winds ...)
best regards / med venlig hilsen