pmul

On 3, Traffic Separation Schemes (TSS) will be making things look tidier (and safer) for many of the more organized flows.

In a TSS, you have to drive on the right, and if you're crossing one, your heading (not your track) must be as close to 90 degrees, to minimize your exposure time. When you're sailing this can be a big pain. The anti-collision rules are altered in a TSS.

The first example won't compile in c++ (can't get a ptr to a non const from a const without something naughty like a const_cast) - that's not undefined behaviour is it?

The first example doesn't produce undefined behaviour as c++ - it just won't compile - you can't initialise that pointer to a non const int from a const int without doing something naughty like a const_cast.