Is it permissible to swim in a pool or in the ocean during the Three Weeks, the period from Shiba Asar Be'Tammuz through Tisha B'Ab? According to the practice of the Sepharadim, it is permissible to swim – both in a pool and in the ocean – during the Three Weeks, and even after Rosh Hodesh Ab. The prohibition against swimming begins only during the week of Tisha B'Ab, meaning, from after the Shabbat that immediately precedes Tisha B'Ab, until after Tisha B'Ab day. Just as bathing is forbidden during the week of Tisha B'Ab, swimming is similarly forbidden. This is the ruling of Hacham Ben Sion Abba Shaul (Israel, 1923-1998). There are some authorities who forbid swimming already from Rosh Hodesh Ab. The practice in our community, however, appears to follow the lenient position, that allows swimming until the week of Tisha B'Ab. Summary: It is permissible to swim during the Three Weeks, except during the week of Tisha B'Ab, meaning, from after the Shabbat that immediately precedes Tisha B'Ab, until after Tisha B'Ab day.