可上山，勿下海。 也可以理解为： 可以去山里生活，但不要去海上生活。因为中国主要是农耕文明，所以“老话”认为耕作比打渔更稳定，更好。 As a Chinese we can go to the mountains to live a life but do not go to the sea. Because the civilization of China is mainly farming civilization, so the old saying perfer farming than fishing. 大大小小 指的是遇到的危险情况，有的大，很严重。有的是小事，不严重。整个出海经历中，有很多危险情况。 Refers to the dangous situation, some of them are very serious. Some are small, not serious. There are lots of dangerin the whole sea-experience thing.