The science of meteorology is a fundamental part of any type of ocean navigation. In the case of yacht racing, it's importance is even greater, given that the wind is the force propelling the boat and is the key factor in formulating the strategy and tactics needed to win. However, the lead role of meteorology in a regatta is for safety, and that is something that the race organisers always make a priority. In Module 4.1 the general climatology for a regatta such as the Barcelona World Race is described, as well as the preparations the skippers make with the sails, the boat and other personal kit. In Module 4.2 you will learn how the Race Management of a regatta work together with the meteorologist to ensure that the information reaches the boats and to guarantee the maximum safety levels for the crews. In Module 4.3 the type of information the crews receive whilst out on the oceans is described, as well as the telecommunications systems used to make this happen. In Module 4.4 you will learn how weather information impacts on safety and you will look at the specific case of ice detection in the Southern Ocean.