Attempting the long sea passage in these boats is extremely dangerous.

乘坐这些船只走漫长的海陆非常危险。

(2) At least one hour before starting or ending a sea passage?

(2) 海上航行开始或结束前至少一小时？

I slipped into my seat, and remarked idly, in answer to Poirot's greeting, that an hour's sea passage from Calais to Dover could hardly be dignified by the epithet " terrible" .

我溜进我的座位，回应波洛的问候，漫不经心地说，从加来到多佛的一个小时的海上航程几乎不能用“可怕”这样的形容词来形容。