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                                                                     EXHIBIT 8.1
 
                              COVINGTON & BURLING
                         1201 PENNSYLVANIA AVENUE, N.W.
                                 P.O. BOX 7566
                          WASHINGTON, D.C. 20044-7566
                                 (202) 662-6000
 
                                 JULY 20, 1995
 
ELDORADO BANCORP
17752 EAST 17TH STREET
TUSTIN, CALIFORNIA 92680
 
MARINERS BANCORP
111 CALLE DE INDUSTRIAS
SAN CLEMENTE, CALIFORNIA 92672
 
LADIES AND GENTLEMEN:
 
     You have requested our opinion as to whether the discussion in the Joint
Proxy Statement/Prospectus (as defined below) under the captions "Summary -- The
Merger -- Certain Federal Income Tax Consequences" and "The Merger -- Certain
Federal Income Tax Consequences" fairly describes certain of the relevant
federal income tax consequences of the proposed Merger (the "Merger") of
Mariners Bancorp ("Mariners") into Eldorado Bank ("Eldorado Bank") in exchange
for cash and stock of Eldorado Bancorp ("Eldorado"), as described in the
Registration Statement on Form S-4 (the "Registration Statement") including the
joint proxy statement/prospectus (the "Joint Proxy Statement/Prospectus") that
forms part thereof.
 
     Our opinion is based on our understanding of the relevant facts concerning
Mariners, Eldorado, Eldorado Bank and the Merger as set forth in the Joint Proxy
Statement/Prospectus. In this regard we have examined and are familiar with: (i)
the Registration Statement including the Joint Proxy Statement/Prospectus and
all exhibits thereto; and (ii) such other documents as we have considered
necessary for rendering these opinions. For purposes of this letter, we have
assumed the accuracy of all information contained in these documents, the
authenticity of all original documents, the accuracy of all copies, and the
genuineness of all signatures. We also have assumed for purposes of our opinion
that Mariners, Eldorado, and Eldorado Bank have been organized and have operated
at all times in accordance with their respective articles of incorporation,
applicable local laws, and the descriptions of the businesses of Mariners,
Eldorado, and Eldorado Bank contained in the Registration Statement.
 
     Our opinion is based on the Internal Revenue Code of 1986, as amended (the
"Code"), regulations promulgated thereunder by the United States Treasury
Department (the "Regulations"), Internal Revenue Service rulings, and court
cases interpreting the Code and Regulations, all as in effect as of the date of
this letter. Any of the statutes, Regulations, rulings, or judicial decisions
relied upon could be changed, perhaps retroactively, to affect adversely the tax
consequences of the Merger. Although the opinions expressed in this letter are
based on our best interpretations of existing sources of law, no assurance can
be given that such interpretations would be followed if they become the subject
of judicial or administrative proceedings.
 
     We have assisted in the preparation of and have reviewed the sections of
the Joint Proxy Statement/ Prospectus entitled "Summary -- The Merger -- Certain
Federal Income Tax Consequences" and "The Merger -- Certain Federal Income Tax
Consequences." We are of the opinion, subject to the qualifications,
limitations, and exceptions set forth in such sections, that such sections
fairly describe certain of the relevant United States federal income tax
consequences of the Merger to Mariners shareholders as of the date hereof
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and constitute our opinion as to such matters. We are expressing our opinion
only with respect to the foregoing matters and no opinion should be inferred as
to any other matters.
 
     We hereby consent to the filing of this opinion as an exhibit to the
Registration Statement. We also consent to the references made to Covington &
Burling in the Joint Proxy Statement/Prospectus under the headings captioned
"Summary -- Merger -- Conditions to the Merger; Termination," "Summary -- Merger
- -- Certain Federal Income Tax Consequences," "The Merger -- Conditions to
Consummation of Merger," "The Merger -- Certain Federal Income Tax
Consequences," and "Legal Matters."
 
                                          Sincerely,
 
                                                   COVINGTON & BURLING
 
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                                                   Covington & Burling