Hi Geoff. How long ago is it since you were a boy?. That would help a bit! The Royal navy used a lot of paddletugs at portsmouth, particularly for handling aircraft carriers. There were also several modern paddle tugs (diesel electric power DIRECTOR class) also operating there. Can you remember, did it have one funnel or two,(in front of each other (steam) or side by side (diesel). Were the funnel(s) tall or small and did they emit a lot of smoke? Were they black hulled with a buff/yellow upper works (fleet auxiliary). Any of the above plus a rough date would help to pinpoint it! regards, walter.