Three of Britain's four Vanguard-class nuclear submarines are at sea, Sky News and The Times reported, citing sources. An anonymous expert told "Sky News" that at least one of the submarines carries nuclear-tipped ballistic missiles and conducts routine patrols. According to the source, apparently another vessel is preparing to go on tour, and it is possible that a third is undergoing sea trials. The Times source called the submarine activity "abnormal". It is rare to have three such submarines at sea at the same time. Such a deployment could be spotted by both the country's adversaries and its NATO allies, and could also be used to send a signal to potential adversaries. The increase in the number of submarines at sea may signal an improvement in the readiness of the British Navy, which "has been a problem" in recent years. RBC channel at max.