Naval power actually played a critical role in shaping the course and outcome of the First World War. Throughout the war, the strength of the British Navy proved one of the most critical advantages held by the Entente Powers over the Central Powers (one that would only grow more powerful as the war waged on).
Remember, by this point in time, the British navy had long been established as the most powerful in the world (and this superiority was still very much in effect throughout World War I). This naval superiority allowed Britain to effectively keep Germany under blockade, cutting it off from imports and thus placing severe strains on the German economy. Unable to compete directly with British naval power, Germany ultimately turned toward submarine warfare instead as a counter to the British blockade.
Of course, submarine warfare had severe diplomatic costs. Submarine warfare was only effective when it was carried out without warning, and thus, its use resulted in large civilian casualties that a conventional blockade would not share. Even so, however, the strategic picture remained clear: submarine warfare remained the only resource through which Germany could conceivably compete against British naval superiority and place pressure on Britain's economy in turn.
Germany's use of submarine warfare would, in turn, serve as one of the critical motivations that would later draw the United States itself into the war. With both the Entente Powers and the Central Powers having exhausted themselves, the intervention of the United States proved a key tipping point critical in shaping the war's conclusion.