run in with some navy vessels

Last night we went out for a cruise around the area. Anyone heard of Hungington Beach? There's a channel to get into Hunginton Harbor (the same channel is used to get into Seal Beach for the navy weapons station, we went down the channel trying to get into Hungington Harbor, turns out that the channel was closed off because they had their navy ship leaving. Two smaller boats with 50 cal machine guns on the front of them came out to meet us. They made sure we left because we got an escort out. How were we supposed to know that the channel was closed off?

That's ok, years ago we were target shooting (with a backstop) in the Mojave Desert. Some AP (Air Police) came riding up in their jeep and told us to please leave as we were on a "government preserve", namely Edwards AFB.
Yes we left but there weren't any signs or we wouldn't have stopped there.