Nautilus Increases Mineral Resources

VANCOUVER, BRITISH COLUMBIA--(Marketwire - Nov. 25, 2011) - A successful exploration drilling campaign conducted at Nautilus Minerals' (TSX:NUS)(AIM:NUS) tenements in the Bismarck Sea of Papua New Guinea has enabled the company to increase the resource estimate at its Solwara 1 project, and to declare a maiden Inferred Resource at the nearby Solwara 12 deposit.

The key features of the resource update, prepared by independent consultant Golder Associates Pty Ltd in accordance with National Instrument NI 43-101, and stated at a copper equivalent cut-off grade of 2.6%, are as follows:

• The company's total Indicated Resources have increased 18% to 1.03 million tonnes.
• Total Inferred Resources have risen 36% to 1.8 million tonnes.
• Contained copper in Indicated Resource at Solwara 1 has increased 25% to approximately 74,000 tonnes.
• Contained copper in Inferred Resource at Solwara 1 has increased 28% to approximately 125,000 tonnes.
• Contained gold in Indicated Resource at Solwara 1 has increased 23% to approximately 166,000 ounces.
• Contained gold in Inferred Resource at Solwara 1 has increased 5% to approximately 317,000 ounces.
• A maiden Inferred Resource has been declared at Solwara 12, 25 km to the north-west of Solwara 1, of 230,000 tonnes, grading 7.3% copper and 3.6 g/t gold.

The increases in contained metal within the resource are a result of additional tonnes, and importantly, higher grades, due to successful resource drilling which identified further high grade ore zones. The increase in tonnes was also partly due to a reduction in the cut-off grade from 4% copper, used in the prior 2008 resource statement, to a copper equivalent cut-off grade of 2.6% in the 2011 resource, following refinements in the project design.

Nautilus Minerals President and CEO Steve Rogers said the notable increase in the company's resource base demonstrated the success of the exploration campaign, extending the life of the Solwara 1 Project and delivering an improved knowledge of the Bismarck Sea geology.

"Importantly, the declaration of a maiden resource at Solwara 12 begins the process of building a pipeline of projects for Nautilus in the region, and confirms the prospectivity of the Bismarck Sea, where we have identified another 16 prospects for further evaluation.

"Nautilus will attempt to build on this base in the coming year, through on-going exploration activities in PNG and elsewhere in the western Pacific," Mr Rogers said.

"Nautilus will be undertaking important work including the use of multi-beam sonar and seismic exploration tools in the Bismarck Sea over the coming months to assist in identifying targets for drilling, scheduled to be conducted in the second half of next year.

"As part of that program we will be testing for additional lenses of high grade material in the vicinity of Solwara 1, while the limits of Solwara 12 have yet to be fully identified," he said.

Nautilus Minerals Resource Estimates, 2008 and 2011, as prepared by Golder Associates Pty Ltd.

Note: Resource estimates prepared by Ian Lipton, (BSc (Hons), FAusIMM), Principal Geologist, Golder Associates Pty Ltd, Toowong, Queensland, Australia who fulfils the requirements to be a "qualified person" for the purposes of NI 43-101 . Rounding may result in errors in reproducing the totals from the individual components shown in this table. Copper equivalent (CuEq) = 0.915*Cu+0.254*Au+0.00598*Ag.

The 2011 Resource is estimated based on 276 drill holes and a cut-off grade of 2.6% CuEq and at an effective date of November 25, 2011. The CuEq grade calculation includes allowances for metallurgical recovery (91.5% for Cu, 45% for Au and 50% for Ag) and smelter payable metal. Metal prices used for the 2011 CuEq cut-off grade calculation are US$3.90/lb Cu, US$1,510/oz Au, and US$32/oz Ag. Density was assigned to each geological zone based on 890 measurements taken from core specimens. Solwara 1 and 12 were estimated using Ordinary Kriging, with the exception of the Solwara 1 North Zone, which was estimated using inverse distance weighting. Details of the resource estimation process will be provided in Golder's NI43 101 compliant report, which will be available on SEDAR shortly.

The updated resource estimate was prepared following a 1,475 metre, 99 hole diamond drilling campaign conducted in the Bismarck Sea from November 2010 until May 2011.

Drilling was focused within the area of the Mining Lease (ML154) granted to Nautilus earlier this year, which contains the Solwara 1 deposit. A total of 71 holes was drilled in ML154, for 1147 metres. The remainder of the drilling was conducted in Exploration Lease 1374, which hosts Solwara 12.

Links

Figure 1: http://www.nautilusminerals.com/i/pdf/PNGNautilusTenementsNov2011.pdf

Certain of the statements made in this news release may contain forward-looking statements within the meaning of the United States Securities Exchange Act of 1934 and forward-looking information within the meaning of applicable Canadian securities law. Forward-looking statements and forward-looking information include, but are not limited to statements or information with respect to the mineral resources of the Company. The forward-looking statements and information contained herein include numerous assumptions. Please refer to the Company's most recently filed Annual Information Form in respect of material assumptions and risks relevant to forward looking information. Even though our management believes the assumptions made and the expectations represented by such statements or information are reasonable, there can be no assurance that the forward-looking statement or information will prove to be accurate. Forward-looking statements and information by their nature involve known and unknown risks, uncertainties and other factors which may cause the actual results to be materially different from any future results expressed or implied by such forward-looking statements or information. Such risks, uncertainties and other factors include, among others, the risk that the amount of metals contained in the Company's deposits may differ from estimates of resources. Should one or more of these risks, uncertainties or other factors materialize, or should underlying assumptions prove incorrect, actual results may vary materially from those described in forward-looking statements and information. Although we have attempted to identify factors that would cause actual results to differ materially from those described in forward-looking statements and information, there may be other factors that cause actual results, performances, achievements or events to not be as anticipated, estimated or intended. Also, many of the factors are beyond our control. There can be no assurance that forward-looking statements or information will prove to be accurate, as actual results and future events could differ materially from those anticipated in such statements. Accordingly you should not place undue reliance on forward-looking statements or information. Except as required by law, we do not expect to update forward-looking statements and information as conditions change and you are referred to the full discussion of the Company's business contained in the Company's reports filed with the securities regulatory authorities in Canada.

About Nautilus Minerals Inc.

Nautilus is the first company to explore the ocean floor for polymetallic seafloor massive sulphide deposits and is developing its first project at Solwara 1, in the territorial waters of Papua New Guinea, where it is aiming to produce gold, copper and silver. The company has been granted all necessary environmental and mining permits.

Nautilus also holds approximately 600,000 square kms of highly prospective exploration acreage and tenements under application in the western Pacific; in PNG, the Solomon Islands, Fiji, Vanuatu and Tonga, as well as in international waters in the eastern Pacific.

A Canadian registered company, Nautilus is listed on the TSX and AIM stock exchanges and has its corporate office in Brisbane, Australia. Its major shareholders include Metalloinvest, the largest iron ore producer in Europe and the CIS, which has a 21% holding, and global mining group Anglo American, which holds an 11% interest.