This is the nearest all tide mainland port to the Scillies, however Newlyn is a fishing port and fishing boats have priority over leisure craft and visiting yachts for the matter - and that includes the limited access to water and shore power. Suffice to say, visiting yachts really only come to Newlyn as a port of refuge, and by all accounts even that's a pretty desperate measure. If you haven't guessed it, yachts really aren't welcome, and the harbour authority here goes out of its way to make it known. The new pontoons in the centre of the harbour, despite looking like a marina, were specially funded by an EEC Fisheries Grant, therefore the local fisherman view these pontoons as 100% commercial.
Ashore you'll find shops for provisions, cash points, and a chandlery and given the standard of hospitality you'll receive that's all Newlyn is good for. A pity really, because with all the locally caught fish there's a healthy selection of fine restaurants in town and one feels why Newlyn can't take a leaf from say Brixham's success where commercial fishing and leisure co-exist in harmony. For showers and toilets etc, I'd give them a miss and stay onboard. The facilities at the Fishing Market involves a tiresome chase of the key holder at the security office and other facilities are at the local Missions to Seaman.