This may surprise you, but the problem of updating charts has been encountered before. And solved. In the early nineteenth century by Admiral Beaufort. The Hydrographic Office issues weekly '
Notices to Mariners' which list the changes to be made to charts. These include shifting sandbanks, new navigational bouys, new survey data and yes, new wind turbines. As far as navigation is concerned it's not a new island it's a new wind turbine. If the captain was unsure of his position the sight of one (and it would be visible at some distance) would give a clue as to his position.