Why warships rarely fire merely to announce their presence

Do warships fire their guns without seeing a target to deter attackers, as tanks sometimes do?

Rarely, because the shot reveals the ship and naval combat usually does not place unseen opponents at such short effective ranges.

A tank can be within effective range while terrain still hides the opponent. A warship is less often in that exact position because naval weapon ranges and lines of sight are much larger. Firing without a target also gives away the ship's location. Surface combatants therefore rarely shoot simply to discourage an unseen attacker or prove they are present.