Cute tiny ship. Could we know bit more about it's background?
Here's one that was even more often under water.
Another minor riverine icebreaker from lower Wisła river, and one with very interesting history. Fribbe (named after a river - practically a stream - now named Fryba or locally sometimes Browina) was built in 1897-1898 at J. W. Klawitter shipyard in Danzig (Gdańsk) for Königlischen Preuβische Staat Weichsel-Strombauverwaltung (Royal Prussian Wisła Water-engineering Administration) as a liaison icebreaker (used to maintain communications between 'major' icebreakers in the pre-radio era) capable of breaking ice thick up to 15 centimeters. It was 17,65 metre long and was powered with two double-expansion steam engines of 40 hp each, allowing it to reach speed of 13,85 kilometers per hour (yes, it wasn't given in knots) on calm waters. During its service it was stationed in Dirschau (now Tczew) and participated in icebreaking operations during each winter, while in the warmer months it was used as a tugboat. Unfortunately, it's small size and relatively weak (for the output it sometimes had to provide) propulsion meant that it frequently suffered significant damage.
After the Great War majority of lower Wisła icebreakers were transferred to Der Hafen und die Wasserwege von Danzig (Harbor and Waterways of Free City of Gdańsk), but Fribbe was one of the few vessels passed to Polish authorities. Due to its poor technical shape it had to undergo a refit, after which it was operated by Zarząd Rzeki Wisły (Wisła River Administration), renamed Wrobna (after E. Wrobna, who was first Polish manager of lower Wisła waterways but who died just 2 months after his appointment) and based again in Tczew. Under new flag it still suffered from a number of mishaps, which culminated on 15 February 1928, when during icebreaking operation it ran aground and was unable to leave it. Crew managed to turn off the boiler (preventing explosion) and evacuate mere seconds before the piling ice literally cut off whole superstructure and smokestack, tipped the vessel to one side and pushed it underwater. Wreck was raised two months later and towed to Tczew, where it was moved ashore, awaiting decision on it's fate. Initially it was planned to scrap it, but because of the extreme shortage of icebreakers, it was finally decided to reconstruct and heavily modernize it.
Contract for rebuilding the ship was won by Bydgoszcz riverine shipyard of Lloyd Bydgoski S.A. (until 1920 Bromberger Schleppschiffahrt AG). New design called for lenghtening of the hull to 24,3 metres (together with more draught), replacing two steam engines with single diesel (6-cyllinder Deutz of 180 hp), complete restructuring of internal arrangement, new superstructure and equipment. Works lasted much longer than anticipated and it also faced huge cost overruns. Shipyard demanded more money from the state, state - represented by Dyrekcja Dróg Wodnych (Waterways Management) demanded payment of contractual penalties by the shipyard. Eventually case went to court, which - in late 1933 - ordered shipyard to finally hand over ths ship to DDW and payment of penalties.
Rebuilt icebreaker, now named Rekin (Shark) was again based in Tczew and served until September 1939 when it was scuttled by Polish crew in order to prevent it from falling into German hands. Germans then raised it, renamed initially Falke (Falcon) and in 1941 Hai (again Shark) and used until spring of 1945, when it was scuttled by Germans in order to prevent it from falling back into Polish hands. In 1946 it was raised again, repaired in shipyard at Pleniewo (now part of Gdańsk) - again as Rekin - and now homeported at Łożyska (now Gdańsk-Przegalina) but generally operated from Tczew. In 1948 its engine block has cracked, necessitating it's replacement with 6-cyllinder Gray Marine 150 hp engine. In 1953 it developed cracks in the hull plating, so it went to shipyard again, and "by the way" it had also engine replaced once again, this time into 8-cyllinder Superior Industries 160 hp. In this form it served until 1964 when it was renamed Żbik (Wildcat) and year later had engine replaced again
- but for the first time the engine wasn't second-hand/surplus one, but a brand-new 6-cyllinder DM-150 made by Zakłady Mechaniczne imienia Marcelego Nowotki (Mechanical Works named after Marceli Nowotko) in Warsaw. In 1973 it was transferred to Przedsiębiorstwo Budownictwa Wodnego (Water Construction Enterprise) in Tczew, which used it now only as tugboat until 1980, when, for technical reasons it was retired to be an accomodation vessel, in which capacity it served until 1984, when it was - sadly - scrapped after 86 years of service.
Waldemar Danielewicz; Historia pewnego mitu. Lodołamacz Rekin - weteran dolnej Wisły; Morze, Statki i Okręty, 4/2009;
Forum Dawnego Tczewa; Lodołamacze i lodołamanie - https://dawnytczew.pl/forum/viewtopic.php?t=1772