As a fellow dog owner I can't see a problem taking them with you BUT with the average person in this country instilled with fear by anything the government decides is "EVIL" you will probably get a lot of grief if you turn up with a "baby eating pitbull lookalike" and a "vicious" German Shepherd.
Until recently I had a Staffie that people used to run away from! Now she was the most chilled dog I have ever had but the perception was that all Staffies eat children so the abuse I used to get was unreal. Ask your dad what she was like as he met her a couple of times. Big soft lump!
Other than that I am sure that they will not be a problem. They do look relaxed on the canoe and they look like a lot of fun. I have met some pretty badly behaved Labs on some salmon rivers that should be shot as well as some owners that should also go that way so your two will be no problem.
I, on the other hand, cannot take my viscious beast anywhere near the river. The rakin' aboot little sh1t would be down every hole in sight and would be off worring otters, sheep, deer, crows and fish if I hooked one. Then she would mooch like a begger at lunchtime and moan if her bed wasn't there to lie in the sun.
It's the wee one not the big one,