A few people in this thread have talked about whether canoing is still permitted.
DH canoes and knows a lot of instructors with professional qualifications or are serious paddlers.
They have ALL stopped paddling. This is because of the insurance issues or because if they have an accident they will be putting pressure on the NHS / putting themselves in a position where they might be more likely to catch Covid-19 because they are attending A & E unnecessarily.
There are also issues over which waterway you are using. It depends on the water way which you use. Some (like canals) require you to have a permit to use them. Many people are not aware of this. If you are paddling on one of these without a permit you could be stopped. Normally you might well get away with it, but under the current circumstances you might be challenged. Others have been officially 'closed' by those who run the waterways.
The Canal and River Trust and the Environment Agency have asked boaters to avoid all non-essential travel on their managed waterways. This is the advice that has been put out via Canoe Wales, British Canoeing
www.canoewales.com/covid-19-guidance-for-clubs-and-course-providers
www.britishcanoeing.org.uk/news/2020/british-canoeing-coronavirus-update-on-paddlesport-activity
26th March Update
In addition the canal and river trust have said
"Use of canal tow paths should now be limited"
canalrivertrust.org.uk/enjoy-the-waterways/safety-on-our-waterways/coronavirus
So no you SHOULD NOT be canoeing. Even if it does not disrupt anyone else.
At present it does depend on where you, and technically it is something of a grey area, you should be aware that some police forces are being very aggressive over how they are dealing with people who go against guidelines, but you might find that they ARE able to deem what you are doing as non-essential and can not be counted as a form of exercise because the owners / those who are responsible for those waterways have put out advice stating you shouldn't be doing it. If the police did decide to take a hard line against you, you might have a hard time defending yourself, again because those waterways are 'closed' for leisure purposes.
I hope this answers the question one and for all, and that people are now clearer on what the position is with regards to canoeing.