A man who was caught snorkelling twice in the National Gallery of Victoria's moat is being held by police and charged with a series of offences.

St Kilda Road police officers charged Gary Makin, 38, of no fixed address, on Friday evening with a string of offences.

Pedestrians watched in bemusement as the man swam in the NGV moat.

Makin was taken to St Kilda Road police station and charged with theft, handling stolen goods, going equipped to steal and possessing the proceeds of crime.

He was refused bail and was remanded overnight to appear before the Melbourne Magistrates Court on Saturday.

Makin was fished out of the St Kilda Road moat on Thursday and again on Friday He was lodged for drunk and handed a penalty notice at that time. Police allege he was skimming the moat for coins tossed into the moat.

Police are appealing to anyone who may have witnessed a man swimming around in the moat on Friday to please contact Crime Stoppers on 1800 333 000 or visit www.crimestoppers.com.au.