Here's another question for the Scotland experts:

My husband and I are taking my parents to Scotland next May. They mentioned that they would like to take a boat / day trip on the Caledonian Canal. I think the idea they have is to find a place to park the car, get on a boat and travel a length of the canal, and then take a train back to where the car is parked -- as a day trip.

I've seen several websites for boat lets for canal cruising, although these seem to be for a week's trip, and I've seen some websites for day trips on Loch Lomond.

We are tentively going to be based around Dalwhinnie.

Is what they want to do possible? I don't think the Loch Lomond trip is quite what they had in mind, I think they're thinking more in terms of going through lock and such, but before I talk to them about this more, I'd like to know what our choices are.

Try these two web sites.

http://www.jacobite.co.uk/
http://www.highlandvoyages.co.uk/diary.html

Neither one offers exactly what you want but they do have day cruises. Your exact plan is a bit difficult since no trains run between Inverness and Ft William along the Caledonian Canal.

I think you're best option will be Jacobite. I can't find anyone doing day trips the length of the canal. You'll see they have a range of options and it might be worth seeing if any of teh combined tours would be worth it for your folks.

Jacobite certainly seems the most appropriate. From Inverness, the boat goes along the Canal and through a lock before entering Loch Ness. You can land at Urquhart Castle and return by bus or boat. There are also short trips from Fort Augustus at the southern end of Loch Ness (www.cruiselochness.com), but these don't go through any locks. There is no railway along the route of the canal, but buses run between Inverness and Fort William via Fort Augustus.
If you're interested in canals, you could also visit the Falkirk Wheel (www.thefalkirkwheel.co.uk), an amazing structure near Edinburgh.

There's a great article about boats Loch Ness in today's Scotland on Sunday by Magnus Linklater (spits!)
http://scotlandonsunday.scotsman.com...?id=2335312005

Inverness to Fort William is 65 miles by road, presumably about the same by water. It seems like a long way for a day trip, bearing in mind that these boats are not built for 20+ knots. It might be possible to do it in two days with a stop en route.
Dalwhinnie is not too far from Inverness as long as you have a car. By rail it's not so good as you'd need a taxi from Inverness railway station to get your boat.
BTW even if you don't go there by boat, the drive from Dalwhinnie to join the Great Glen and Caledonian Canal at Spean Bridge is very scenic.

Up until 1939, MacBraynes ran a summer service by paddle steamer between Inverness and Banavie (near Fort William), taking one day each way. The service was not continued after the war.
If you do the Jacobite cruise from Inverness, they run a minibus from the town centre to connect with the boat, otherwise it's a pleasant walk: details are on their web site.