Traveling on a Ship 2 (Klal 4 Siman 1) Erev Shabbos - S0102

We are beginning Klal 4, siman 1. The Chayei Adam writes that a person cannot leave on a long-term trip in a boat more than three days before Shabbos. The Chayei Adam understands that Wednesday is already assur (i.e., beginning from Tuesday night), although we mentioned that we pasken the issur begins from Wednesday night. The Chayei Adam brings the explanation of the Rif, that the problem is that the first three days are uncomfortable. The Chayei Adam brings the pasuk in Tehillim, which describes sea travel as “one who weaves back and forth as a drunk” (107:27). This discomfort, in turn, will detract from a person’s oneg Shabbos. 
As we learned yesterday, the Mishnah Berurah brings from the Gra that many rishonim hold that the three days include Shabbos, so the issur only begins from Wednesday night. 

The Chayei Adam writes that this issur applies when a person is going for a dvar reshus, a voluntary trip. If a person is going for a dvar mitzvah, Chazal did not place their issur. He explains that we have a rule that oseik b’mitzvah patur min hamitzvah, when a person is involved in one mitzvah, they are exempt from another mitzvah which comes their way later (see more in shiurim 1389-1395). This addresses the loss of the mitzvah of oneg Shabbos. 

The Chayei Adam writes that the Jew should make an arrangement with the non-Jew that the ship should anchor over Shabbos. Even if the Jew knows that the non-Jew will not listen and will keep traveling even on Shabbos, at that point, the Jew has done his part to avoid the non-Jew working on Shabbos, so it is acceptable. 

If the arrangement is such that it is impossible to make such a stipulation, the Chayei Adam writes that some hold it is assur, and some hold it is muttar. The MIshnah Berurah writes that we are only makpid lechatchilla to make such a stipulation. If it is not feasible to make one, it is muttar.

The Chayei Adam points out that it is assur to begin a trip on Shabbos, because it is impossible to make an agreement not to travel on Shabbos if the trip begins on Shabbos. Since the Chayei Adam holds such an agreement is required, he holds it is the reason one cannot travel on Shabbos. The Mishnah Berurah, who held that this agreement is not necessary bedieved, also holds that it is assur to begin a trip on Shabbos, but for a different reason. He holds it falls under the issur enacted by Chazal against swimming on Shabbos.

Regarding the definition of a dvar mitzvah, we are fairly lenient. The Chayei Adam writes that going on a trip for the purposes of parnassa, even if one has enough for their basic needs, will be considered a dvar mitzvah in this context. Having a safety cushion and being able to help others are valid forms of dvar mitzvah. Traveling to make someone happy, or for kibbud av v’eim are also considered valid forms of dvar mitzvah. 

Summary
Chazal made a takana that one cannot board a boat from Wednesday night if the journey will not end before Shabbos. There are multiple understandings as to why Chazal made this takana. The Shulchan Aruch understands, based on the Rif, that the concern is a lack of oneg Shabbos
The issur only applies to a dvar reshus. A dvar mitzvah, which includes parnassa and to make others happy, is muttar.
Lechatchilla, one should try to make a stipulation with the captain that the boat will anchor over Shabbos. However, it is not necessary bedieved.