Radio aids are making a substantial contribution to the safety of yacht navigation, mainly by enabling off-lying dangers to be avoided when making landfall in conditions of poor visibility or overcast sky. The ability to obtain fixes of sufficient accuracy to keep clear of shipping lanes in fog is another important safety factor.

The use of hyperbolic aids, of which Loran is one, is expressly banned in ocean racing both in the U.S.A. (except in the Bermuda race) and the U.K., on account of the high price of the receivers and the advantage they might confer on those who can afford to buy or hire them. Table I shows the systems which are available in British waters, the types of error to which they are prone and some typical accuracy figures obtainable at sea. It is of particular interest to note that the accuracy of the hyperbolic aids, VOR and Consol is unaffected by the motion or attitude of the vessel, or by its metallic structures and rigging; d.f. is subject to errors from all three of these causes and all the systems except VOR are subject to the night-time sky-wave error.