Sounds like a great hike, Catrin! I have one of those 50 oz Camelbak waist packs I have used for years on the bike and hiking. It does a good job. I recently invested in a new small but standard (over the shoulder) Camelbak in large part because I wanted screaming yellow so I don't always feel like I have to wear screaming jersey colors on the bike. My waist pack is blue and just not very visible. I like the smaller size, though, and I believe my new shoulder pack is about the same size. Anything more just gets awfully heavy for me, since I am small as it is.
Glad you were able to get out and hike and do your Tai Chi outside too. I am sure that is a pleasant experience (as I've found outdoor yoga to be) when the weather is nice.
2011 Jamis Dakar XC "Toto" - Selle Italia Ldy Gel Flow
2007 Trek Pilot 5.0 WSD "Gloria" - Selle Italia Diva Gel Flow
2004 Bike Friday Petite Pocket Crusoe - Selle Italia Diva Gel Flow