Development land in the Menai Strait is amongst the lots offered by Sutton Kersh.
The property auction will take place on Thursday 6 December at the Marriott Hotel in Queen Square, Liverpool.
The freehold island, on the narrow stretch of shallow tidal water between Anglesey and mainland Wales, has full planning to rebuild the existing boatyard in Gwynedd and pedestrian access from the mainland to the development land. The island has a guide price of £140,000.
Also up for auction is residential investment property on Edge Lane, Liverpool, currently producing £28,512 a year.
The three-storey, semi-detached property with basement has been converted into five self-contained one-bedroom flats. Each flat is let individually by way of an assured shorthold tenancy and has double-glazing and central heating. The property has a guide price of £165,000.
Sutton Kersh has achieved a selling average of 78% this year after selling 359 properties, generating total proceeds exceeding £25.8m across six auctions.
Cathy Holt, auction manager, said: "Competitive bidding has returned to the auction room which is a positive sign for the market."
Sutton Kersh's first auction of 2013 will take place on 14 February. Entries are now being invited and the catalogue will close on 18 January.