The host cancelled the excursion at 6pm the day before, citing a forecast of rain. In fact the forecast showed only a 15% chance of rain. The day itself was the warmest and driest for several weeks according to a local. However had it rained I imagine it would have been the lighest of showers (as had been the case the day before) and nowhere near sufficient to render the excursion either unsafe or unenjoyable. There was no response from the host to my message requesting a refund. I had to go out of my own way and contact Viator. I now need to wait three to seven working days for my refund to come through. Terrible all round.