A certain author outlined most pertinent questions and concluded to permit swimming on Shabbos [on a now-defunct website].
I do not agree with his conclusions, but all Torah questions require fresh, honest study, especially those arousing cognitive dissonance. We must, as part of the obligation to study Torah, continually reopen what grabs our attention and let the chips fall where they may. Too few Torah scholars today do so, relying instead on various slogans to reinforce unjust habit and Appeal to Authority.
An imprecatory verse from Pirkei Avos comes to mind:
ודלא מוסיף יסף
P.S., Why do I disagree? For one, modern scholars may add prohibitions of permitted activities to the Torah (as long as (1) they are self-consciously doing so and revealing the fact, (2) their reasoning is sound, and (3) there is no unjustified leniency or sin brought about through the new stringency). So the author over here is correct but incomplete.
Examples include not having the Shli’ach Tzibbur pray and say blessings for the congregation, since it is suspected that they do not listen carefully (unlike Chazal’s day), umbrellas on Shabbos (?), some laws of Bassar Bechalav, the Gaon on not going to the Mikveh on Shabbos, et cetera. Perhaps Rambam on Redid might be another.
Do post-Chazal scholars keep up to the three aforementioned standards required? Not always.
There is more to say, but not now.
[The author was made aware of my comments but declined to respond.]