Hi! During the nine days is one allowed to go on a hike that involves walking through water around knee high?
It is not advisable to go on a hike during the nine days. The reason being, that since during these days our mazal is lower, therefore, whenever possible we try to avoid doing things that are dangerous. A person that for some reason has to go on this hike because of a dvar mitzva etc., may go into the water as it isn’t for pleasure, but because he has to get past it.
May H-shem rebuild the Bais Hamikdash b’mehira
O:CH 551-1, Poskim