This article presents, not commonly exposed in literature, issue of a combat operations of 1 Command of 18 Cavalry Regiment of the Pomeranian, which during the July offensive (called Tuchaczewski offensive) in 1920 was situated on the territory of the Republic of Estonia. Cut off from the main force of the Polish Army, it was transported by sea to Gdynia (using the first ship of the Polish Navy), where despite of the lack of port infrastructure has been safely unloaded. This event is obviously based on the wider context of the fighting of 18 Cavalry Regiment in 1920 and it should be noticed in Gdynia and Pomeranian historiography.