2D and 3D Seismic Updates

Rockhopper Exploration plc
25 July 2007


25 July 2007


                               Exploration Update

                     2D prospects and leads volumetric work

                        3D data - initial interpretation


Rockhopper Exploration plc ('Rockhopper' or 'the Company') the North Falkland
Islands explorer, is pleased to announce that volumetric work has been completed
on the Company's leads and prospects in licences PL023 and PL024. The work
suggests unrisked P50 recoverable reserves of in aggregate 2.5 billion barrels
providing encouragement against the backdrop of an easing rig market.


Rockhopper is also pleased to report that it is further encouraged following an
initial review of 3D seismic data covering licences PL032 and PL033, from where
oil was recovered in 1998. The survey is the most modern 3D project undertaken
in the Falkland Islands to date. Significantly, both structural closures and fan
type bodies can already be seen.


2D data - PL023 & PL024 - target sizes


Rockhopper has now completed volumetric work using the 2D seismic data collected
in 2006 on a number of targets in licences PL023 and PL024 which suggests
unrisked P50 recoverable reserves of in aggregate 2.5 billion barrels.


All of these targets are in relatively shallow water depths of less than 200m.
The potential range of target sizes is listed below. The minimum economic size
is likely to be 35 to 50 million barrels recoverable. The Company believes that
the net present value of a single 100 million barrel recoverable oil field would
be between US$750 million and US$1 billion.


Recoverable oil

Millions of barrels (unrisked)


Name          P10     P50     P90


Beauchene     216     145      98

Bleaker       387     193     119

Concordia      60      44      20

Dolphin       543     287      49

Ernest        300     130      50

Golding       125      49       4

Keppel        812     580     365

Pebble        298     186      97

Saunders      679     434     171

Usborne       290     220     150

Weddell       394     254     108



These represent the best 11 structural targets in the opinion of the Directors.
There are a number of smaller additional leads which have not been listed. The
names are taken from Falkland place names. No reserves have been attributed to
any stratigraphic leads which are likely to mature with further data
acquisition.

Ernest, which is a 4 way closure with a positive CSEM anomaly, located in the
North of PL024, remains the most attractive prospect.

3D Data - PL032 & PL033

Rockhopper expects to receive the final processed 3D volume at the end of July.
This 3D covers an area of over 800 square kilometres and extends along some 30km
of the untested eastern basin margin. Data acquisition took place between
November 2006 and January 2007 and the survey is the largest of the three 3D
surveys carried out in the North Falkland Basin.

The Company has already received the initial Quality Control ('QC') volume.
These data are of high quality and represent the most modern 3D undertaken in
the Falkland Islands to date. The QC data volume is the entire data volume,
delivered prior to the completion of processing. It allows the Company to make
an initial interpretation of the data and also to finalise the processing work
required.

The initial interpretation of the QC volume reveals a number of structural
closures and two large fan bodies that can clearly be seen even at this early
stage.

Once interpretation of the final processed 3D data is completed, prospects will
be ranked and drilling locations will be decided.

Pierre Jungels commented:

'The data we have available to us is extremely encouraging and further reduces
our exploration risk in the North Falkland basin. The target sizes in licences
PL023 and PL024 provide confidence in the potential upside should any discovery
be made in the area and with the rig market easing, our work will now focus on
selecting the best targets for drilling.

Oil has already been recovered on licences PL032 and PL033 so the fact that we
can see structural closures and possible fans on our 3D seismic in this area is
highly significant and increases our confidence in the prospectivity of the
acreage.


NOTE

While most of the targets listed above are entirely within Rockhopper acreage,
others straddle the boundary between Rockhopper acreage and unlicensed acreage,
or acreage licensed to other operators. For example, while approximately 95% of
target Ernest (P10) is within Rockhopper acreage, the analysis above relates to
100% of the target.

No risking has been performed in calculating the numbers above. Where targets
are basement structures, a 30m net pay has been assumed. Where targets are
shallower closures, a net to gross of 0.65 has been applied to the volume.
Conservative reservoir parameters have been applied throughout.

NB: This statement has been approved by the Company's geological staff who
include David Bodecott (Exploration Director), who is a Member of Petroleum
Exploration Society of Great Britain (PESGB) and the American Association of
Petroleum Geologists (AAPG) with over 30 years of experience in petroleum
exploration and management, for the purpose of the Guidance Note for Mining, Oil
and Gas Companies issued by the London Stock Exchange in respect of AIM
companies, which outline standards of disclosure for mineral projects.


For further information, please contact:


Rockhopper Exploration plc           www.rockhopperexploration.co.uk
Sam Moody - Managing Director        01722 414 419


Teather & Greenwood Limited
Tom Hulme - Corporate Finance        020 7426 9000
Tanya Clarke - Sales


Aquila Financial Ltd                 www.aquila-financial.com
Peter Reilly                         020 7202 2601
Yvonne Fraser                        020 7202 2609



Notes to editors


www.rockhopperexploration.co.uk

The Rockhopper Group started trading in February 2004 to invest in and carry out
an offshore oil exploration programme to the north of the Falkland Islands. The
Group, floated on AIM in August 2005, is currently the largest licence holder in
the North Falkland Basin and has a 100 per cent. interest in four offshore
production licences which cover approximately 5,800 sq. km. These licences have
been granted by the Falkland Islands government.








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