It does not have to be in the ocean to be offshore racing. Lake Pontchartrain was a long course on relatively flat water. You still had to navigate to find a checkpoint. Detroit River (Wyandotte), you went out into Lake Erie, lost sight of land, had to find 1 or 2 checkpoints in brutal water conditions and then come back to the river. Tampa Bay went into the Gulf. The first Hudson River races had a leg that went out into the Altlantic. Barnegat Bay was only NPBA (regional) racing. And even those races were about 100 miles. Don't know about the other 2.
Fast Shafts, have you ever raced? I'm 42, so age has not gotten that much of my memory. I was fortunate enough to race in 3 of the most crowded classes ever in offshore racing. Pro Stock, and 2 Stock classes. I raced against J.D. D'Elia, Bob Erickson, Pete Aitken, Dom Palombi, Kirk and Alan Dunteman and many, many other great racers. I had what I considered to be the best T-man and rigger in the business, Kurt Berger. I won the World Championships in 1985 and the age of 18 years and 10 months. A record that still stands. I'm not trying to inflate my own ego because I have no need to. Just saying that I have been there and done that.