If it is not now determined whether there will be a sea battle tomorrow, can an assertion that there will be one be true? The problem has persisted because there are compelling arguments on both sides. If there are objectively possible futures which would make the prediction true and others which would make it false, symmetry considerations seem to forbid counting it either true or false. Yet if we think about how we would assess the prediction tomorrow, when a sea battle is raging (or not), it seems we must assign the utterance a definite truth-value. I argue that both arguments must be given their due, and that this requires relativizing utterance-truth to a context of assessment. I show how this relativization can be handled in a rigorous formal semantics, and I argue that we can make coherent sense of assertion without assuming that utterances have their truth-values absolutely.