The first danger in the swan is morass(трясина). It protacts. There can be danger animals. If you got into morass you may not swim, because morass don't have bottom. Cane is dangerous too, it mask morass too. Gas in swan air can be so dangerous too. If you are in swan you don't have much chance to have good help. If you are in big swan you may spend there a lot of time or get lost and don't find end.
