I have no knowledge of this other than it appears on maps around 1950 - The Seaplane Station existed beside Rock Ferry Pier.

Was this another short lived business by a post war pilot or was it a proper service to/from somewhere?

Guess nobody else knows anything about this aerodrome, everything I have found has been around 1930 not 1950 - but it is not unusual for maps to carry forward duff info like this. Anyway here are a few snippets I have found in connection with this, just in case somebody wants to follow up in the future ....

Sept 1928
Flying Boat (Short Calcutta) of Imperial Airways used on the Mersey. Liverpool Maritime Aerodrome was operated by the Mersey Docks and Harbour Board between Rock Ferry Pier and Garston Docks. Only ran from Sep 22 to Oct 4

Story dated January 10 1930
Liverpool Marine Airport Approved
THE Air Ministry has approved, with the concurrence of the Commissioners of Customs and Excise, of the following area at Liverpool as a Customs " aerodrome " for marine aircraft carrying only passengers and light baggage. That portion of the River Mersey bounded on the north by Rock Ferry Pier (Lat. 53° 22'30" N., Long. 2° 59' 45"W.) on the west bank and by a line running true east from the pier and on the south by a line running true west from a position in Garston Docks (Lat. 53° 21' N., Long. 2° 54' 30" W.) on the eastern bank.

Air Ministry Notice published February 14 1930
A map and full particulars of the Liverpool Customs Seaplane Port
appear in the Air Pilot (Volume I) Monthly Supplement No. 5, separate copies of which are obtainable direct from H.M. Stationery Office or through any bookseller at the price of 6^. Net

National Archives
Inter-war flying boat on the river Mersey. M387/MAS/2/55 c. 1928
Inter-war flying boat on the river Mersey (with press cutting). M387/MAS/2/56 c. 1928

No, that's a new one on me.

The picture above is of Imperial Airways' flying boat "City of Athens" being towed by a launch loaned by White Star Line on the river Mersey, September 1928.

It was operated from 'The Liverpool Marine Aerodrome' off Rock Ferry by the Mersey Docks and Harbour Board - this experimental flight to Belfast was the only known service.

The Short S8 Calcutta flying boat G-EBVH had a crew of 2 and could carry upto 15 passengers.

The inaugural flight on Saturday 22 September 1928 carried 12 distinguished guests who were treated to a civic luncheon on arrival at Belfast.

The first week went successfully so it was decided to continue into a second week. However the aircraft was damaged and returned to Southampton for repairs; it never returned, instead it was used on the Channel Islands service - so came the end for the experimental service.

Chris,same as yourself.I did`nt know anything about it myself.A fantastic find.

Bloody hell fantastic didnt even know that

Wow - well done uptoncx - have you got a job down at the archives or summit?