The question is rather vague. There are many different kinds of sentences. Usually when you're talking about "types" of sentences in a general sense, you're talking about the four types (declarative, interrogative, exclamatory, and imperative). In the case of your sentence, it is a declarative sentence since it is making a statement. It is a positive declarative because it is stating that something <em>does</em> happen. If instead the sentence said that the wind and rain and sea do <em>not</em> produce waves then it would be a negative declarative sentence.
