In spring and early summer mirages are formed over sea, due to the cold sea water cooling the incoming warm air. More at https://finland.fi/life-society/mirages-in-finland/

Silja Serenade is 203 meters long and 13 decks high passenger ship sailing between Helsinki and Stockholm. The mirage enlarges the lower decks with the 'Silja Line' text, and hides part of the upper decks.