Back around the mid-late 2000s I discovered a web comic (it could have been a scan of a physical comic) about a dog and his boy who go on adventures, either in space or underwater - perhaps both. I say 'dog and his boy' because the dog could talk and it was possibly the smarter of the two. I think they had their own craft, either a spaceship or a submarine.
It was full-page with a mixture of large images along with smaller panels, was colourful and quite detailed, and to me the artist seemed quite talented. Stylistically I'd liken the characters to Peanuts - the protagonists had small bodies and big heads, the dog had a black circle for his nose. I recall some quite epic set pieces too, reminiscent of the larger Calvin and Hobbes Spaceman Spiff strips (which were quite possibly an influence).
The boy had a non-typical human name, like Zippy or Moppy. Every few weeks a new page would appear, but after several it just stopped.