I remember Charles Dickens saying in one of his tales something about it being hard enough to live with any one who had a bad temper in a large house, but to be shut up with the said person in a cart or travelling van was terrible.  Of course I am not giving his exact words, only making the allusion to illustrate the fact that it is quite as bad to exist with an ill-tempered person in the small cabin of a vessel at sea. For you may depend upon it there is no better--or worse--way of finding out a companion's peculiarities than that.