A Brachah on Rivers

What Brachah do I say when I see a River or an Ocean?

The brachah of Oseh ma’aseh bereishis (thanking Hashem for the wonders of creation) should be reacited when we see a large river that has been around since sheishes yemei breishis (the beginning of creation). 

However, if the river has changed course, even if it happened biyedei shamayaim (due to a natural act from Above), we don’t say the brachah. When encountering a river, we needn’t be concerned that its course may have changed over time, but if it’s unknown whether the river dates back to sheishes yemei breishis, no brachah should be said. This is one of the reasons that this brachah is seldom recited, since the provenance of most rivers is unknown. Poskim say, though, that there is no concern with saying the brachah if we see very large rivers, such as the Mississippi. 

None of the issues concerning rivers apply to oceans; we certainly should make a brachah when seeing an ocean. Upon seeing the “yam hagadol” (the ‘great ocean’), a special brachah, She’asah es (or Oseh) hayam hagadol, ought to be said. However, since we don’t know which ocean bears that name, we say Oseh maaseh breishis instead. Some maintain that the brachah for the yam hagadol should be recited when seeing any ocean which encircles continents, such as the Atlantic Ocean. #479

https://halacha2go.com?number=479

Practical Halacha: One minute a day. By Horav Yosef Yeshaya Braun, shlita, Mara D'asra and member of the Badatz of Crown Heights.