In the absence of contract or custom, there is no requirement at common law for a shipowner to notify charterers of the vessel's readiness to load (or discharge). However, most voyage charterparties call for such notice when the vessel has arrived at a location designated in the charter as the place where notice can be given, and when the vessel is in all respects ready to load. For thirty years, it was accepted that in some cases, if the vessel was not ready when the notice of readiness was given, the notice could be treated as "inchoate" and considered complete when the vessel was thereafter ready to load. Thus, it was neither effective nor invalid when tendered, but could become effective later, that is, as soon as loading began. In 1990, the Court of Appeal rejected the doctrine, notwithstanding arguments that it could be justified by resort to theories of estoppel and waiver, and agreed that only notice valid at the time it was issued could start laytime. In other circumstances, a shipowner may avoid failure to tender a valid notice of readiness by pleading waiver or estoppel on the part of the charterer. Recently, in the case of the Happy Day, the Court of Appeal held that whether charterers had waived valid notice would depend on the effect of the communications or conduct of the parties. In an appropriate commercial context, silence in response to the receipt of an invalid notice - in the sense of a failure to intimate rejection of it - might amount to a waiver of the invalidity. The author suggests protocols for both shipowner and charterer and offers a useful charterparty clause anticipating premature notice of readiness.