River mouths don't seem to have their own classification and you don't need a surf launching ticket to go out through them. I reckon SAMSA are going to change this at some stage. With the amount of boats that has gone belly up in the Breede I am surprised they haven't done something already.
The biggest difference between a river mouth and a normal surf launch is the current.After the flood last year the river is getting a lot more water in and out. There are very few of us who now go through on an outgoing tide. It is just too dangerous. The current is hitting 8 knots on a normal day and in springtide a good 12 knots. That is like a freigh train into a wave, and seeing as the tide pulls at the bit that sticks out the most, then engines, you are bound to be pulled in either rear end first or side on.
About 100m before the bar, in front of Sedgewicks house, there is a set of standing waves on the outgoing tide. Seasoned guys have been caught out by this. The fall into a hole nose first and get completely covered in water.
Anyway, the point was that according to the "rules" river mouths have no special requirements. According to my insurance, the river mouth is very special, th rates are huge.