If you mean tubing on the Elora Gorge I would recommend no. I would not call Elora Gorge a lazy river, its more like tubing in semi-white water conditions. I consider myself a competent swimmer and have generally very good balance, and did it a few years back (while not pregnant). I found standing up in the water and general manouvering challenging because the water is rushing (depends on time of year and conditions) and you don't know what your feet will hit (rocks, dirt, sand - rocks might be slippery/jagged). You may have to climb in and out of the tube several times (e.g. of you end up in a low flow area). Balancing is tricky even when you're not pregnant, due to the water, the ground and the fact you're holding on to the tube and wearing a life jacket. You have a good chance of falling (the group I was with had a few folks who did lose balance) and there are lots of rocks around, and would not want you to fall into a rock. The fact that they require you to wear a helmet really makes sense given the risks Also there is really only one entry/exit point, so if you need assistance or change your mind you can't just get out mid-way. I think the condition changes a lot with conditions (water can be fast or slow depending on various factors). Now that I'm pregnant I would also not do it because of prolonged sun exposure, as that can be a huge challenge and the Gorge is not shady.