That link has ALWAYS given the warning. Don't worry about it. I have been using it for many years with absolutely no problems. Excellent site - I am fairly certain that the generally reliable Passageweather.com - among other sites - gets their data directly from the Navy site.
"Before you criticize someone, you should first walk a mile in their shoes. That way, when you DO criticize them, you'll be a mile away and you'll have their shoes." Stephen Wright.