Cruise

Casual layers (elasticated waists!) and comfortable walking shoes for shore excursions.
We had to change for dinner because the weather was hot and our day clothes got sweaty. The laundry service was worth every penny.
The supplied toiletries were lovely.

casual staff

I have seen a few people change for dinner on a river cruise, not many. There have only been 90-200 passengers on the vessels we have traveled. I like the casual dress. Jeans and Ts are fine too, I forgot to add to my list.

Most people wear smarter for dinner that they have worn during the day but don't 'dress' for dinner. And, a bit more bling for the captain's dinner if you feel like it.

On the river cruises we have done there is usually a range of people - from those who enjoy dressing up and those who don't - either is fine!

River cruises are usually much more relaxed than the ocean ones. Casual stuff as already mentioned is enough.

Where? When (weather)? How long?

I never dress for dinner on a River Cruise. I just wear trousers, tops, jumpers, and a rain or wind jacket.

Binoculars

Smart casual.

Sounds nice!

How long are you going for and where is the river?