Caledonian river cruises

It looks like you are talking about this company- https://www.caledonian-discovery.co.uk/

I've not heard of them before, as I've cruised the Great Glen/Caledonian Canal on the Lord of The Glens- https://lordoftheglens.co.uk/

(a private yacht or Scottish Country House type of experience). Nor have I seen their barges.

There are no real river sections- you have a series of long broad lochs punctuated by several canal sections. The canal sections you will see the same if you walk them from the boat on the towing paths, rather than stay aboard.
On the Loch sections there are few landing locations. If you go hiking or biking it will be in the surrounding hills as there are no substantive cycling/walking sections at Loch Level. The lack of jetties (docks to you) means you can't just hop on and off at will. Me I would prefer the luxury of the barge to sailing or kayaking the same water- bearing in mind that Loch Ness especially can really get rough but that's just me.
It looks a lot of fun just to sail on board them, not partaking of the sports activities. Being finicky I think they are look alike barges, not converted old ones which traded. Probably very different to the grandeur of the Lord of the Glens.

The fact that Loch Ness can be dangerous is borne out by the Loch now having it's own inshore RNLI lifeboat station.

You can also charter "self-skipper" boats in Inverness and Laggan for which there are lots of Youtube travel blogs. We've done such boats in France and Ireland and enjoyed them immensely, although they are sort of "slow tourism" that diverts from other possibilities. We'll do one in a few years when we start running out of places we want to go.