The phrase "loosing for sea" relates to the act of departing or sailing away from shore. However, there are various synonyms that can be used in place of this term. One alternative phrase is "setting sail," which implies the beginning of a journey on a ship. Another synonym is "embarking," which denotes the process of initiating a voyage. "Launching" is also a suitable synonym, suggesting the movement of a vessel into the water. Finally, the phrase "casting off" can be used to describe the separation of a ship from the dock or mooring. These synonyms for "loosing for sea" offer a range of expressions to describe the act of sailing away.