Night caller

Last night, moored up in the middle of nowhere, we were both woken about 3.0 a.m. by a distinct 'thud' on the outside of the boat. It wasn't really heavy enough to be a person (well that's my excuse for not getting up to investigate) so we lay awake for a while listening. All was silent and we drifted back to sleep.
Next morning the evidence was clear for Sherlock Starwoman to investigate. "It seems to have come aboard at the tippet, started to go along the outside gunwale, decided it was too close to the water and gone along the other side to the front instead. You can see that it seems to have shook water off itself here (points to small dirty marks on deck) and jumped up here (points to locker). But what was it, Watson?"
Well I reckon a cat out for a prowl – even though we were a long way from any house. Sherlock is still not convinced. What do you think? They're small prints - little more than an inch long so it wasn't a mystery puma!