In Biggles Sees Too Much, Sam Pretty is a retired mariner or fisherman who spends his time lounging on the quayside of the Cornish village of Polcarron.
While Biggles was on holiday at Polcarron, he spent much time in the company of Sam. Sam was an inverterate story teller and Biggles found his yarns rather boring and tedious but at least he provided some useful background about the shark-fishing industry which a gang was using as a cover for a people-smuggling racket.
His powers of observation and garrulousness proved useful to Biggles time and again in the course of the investigation. In one instance, he saw that the cabin cruiser run by Stephen Brunner appeared to have caught a shark, but he could tell that it was more than a week old, and he had seen that same fish being used on at least one if not two previous occasions, thus reinforcing Biggles' suspicion that the activities of the boat were fraudulent. On another occasion, he told Biggles he was convinced the barman of the Fishermen's Arms, Tom Draper had been murdered. On the night of his death, he had seen someone following Tom along the path up the cliffs.