<PAGE>   1

                                                                    EXHIBIT 10.3

                           AMENDMENT NO. 3 AND WAIVER

                 This AMENDMENT NO. 3 AND WAIVER ("Amendment") is made as of
June 23, 1997 by and among DI INDUSTRIES, INC., a Texas corporation (the
"Company"), DRILLERS, INC., a Texas corporation ("DI" and with the Company the
"Borrowers"), each of the Subsidiary Guarantors party thereto (the "Subsidiary
Guarantors"), the lending institutions from time to time party thereto (each a
"Lender" and collectively the "Lenders") and Bankers Trust Company, as Agent
and Administrative Agent, and ING (US) Capital Corporation, as Co-Agent and
Documentation Agent. This Amendment is made with reference to that certain
Amended and Restated Senior Secured Revolving Credit Agreement dated as of
December 31, 1996 by and among the Borrowers, the Subsidiary Guarantor, the
Agent and the Co-Agent and Nordlandsbanken ASA, as a Lender (as amended to
date, the "Credit Agreement"). All capitalized terms used herein and not
otherwise defined shall have the meanings assigned to such terms in the Credit
Agreement.

                 Whereas, the Borrowers, Subsidiary Guarantor, Agent, CO-Agent
and the Lender entered into the Senior Secured Reducing Revolving Credit
Agreement on December 31, 1996 (the "Initial Agreement"); and

                 Whereas, the Borrowers, Subsidiary Guarantor, Agent, Co-Agent
and the Lender have amended and restated the Initial Agreement by entering into
an Amended-and Restated Senior Secured Revolving Credit Agreement on April 30,
1997 (the "Amended and Restated Agreement"); and

                 Whereas, the Borrowers, Subsidiary Guarantor, Agent and
Co-Agent have further amended the Amended and Restated Agreement by entering
into Amendment No. 2 and Waiver on June 6, 1997; and

                 Whereas, the Borrowers, Subsidiary Guarantor, Agent, Co-Agent
and the Lender desire to further amend and waive certain terms of the Credit
Agreement as set forth below in order to accommodate the transactions described
in the Company's Registration Statement under the Securities Act of 1933 on
Form S-3, as amended, as filed with the Securities and Exchange Commission on
June 6, 1997.

                 Now, therefore, for good and valuable consideration, the
receipt and sufficiency of which are hereby acknowledged, the parties hereto
agree as follows:
<PAGE>   2
                                      -2-



                       SECTION 1. AMENDMENTS AND WAIVERS

                 1.1.     Section 8 of the Credit Agreement is hereby amended
by adding a new Section 8.04(j) as follows:

         "and (j) Indebtedness evidenced by the Company's Senior Notes due 2007
         in an aggregate principal amount up to $175,000,000."

                      SECTION 2. RATIFICATION OF AGREEMENT

                 2.1.     To induce the Required Lenders to enter into this
Amendment, each Borrower represents and warrants that after giving effect to
this Amendment no violation of the terms of the Credit Agreement exist and all
representations and warranties contained in the Credit Agreement are true,
correct and complete in all material respects on and as of the date hereof
except to the extent such representations and warranties specifically relate to
an earlier date in which case they were true, correct and complete in all
material respects on and as of such earlier date.

                 2.2.     Except as expressly set forth in this Amendment, the
terms, provisions and conditions of the Credit Agreement and other Credit
Documents are unchanged, and said agreements, as amended, shall remain in full
force and effect and are hereby confirmed and ratified.

                     SECTION 3. COUNTERPARTS; EFFECTIVENESS

                 This Amendment may be executed in any number of counterparts,
and all such counterparts taken together shall be deemed to constitute one and
the same instrument. Signature pages may be detached from counterpart documents
and reassembled to form duplicate executed originals. This Amendment shall
become effective as of the date hereof upon the execution of the counterparts
hereof by each of the Borrowers, the Subsidiary Guarantor and the Required
Lenders.
<PAGE>   3
                                      -3-

                            SECTION 4. GOVERNING LAW

                 THIS AMENDMENT SHALL BE GOVERNED BY, AND SHALL BE CONSTRUED
AND ENFORCED IN ACCORDANCE WITH, THE LAWS OF THE STATE OF NEW YORK, WITHOUT
REGARD TO PRINCIPLES OF CONFLICT OF LAWS.

              SECTION 5. ACKNOWLEDGMENT AND CONSENT BY SUBSIDIARY
                                   GUARANTOR

                 The Subsidiary Guarantor hereby acknowledges that it has read
this Amendment and consents to the terms hereof and further confirms and agrees
that, notwithstanding the effectiveness of this Amendment, its obligations
under the Guarantee shall not be impaired or affected and the Guarantee is, and
shall continue to be, in full force and effect and is hereby confirmed and
ratified in all respects.
<PAGE>   4
                                     -4-

                 Witness the execution hereof by the respective duly authorized
officers of the undersigned as of the date first above written.

<TABLE>
<S>                                                                 <C>
BANKERS TRUST COMPANY,                                              DI INDUSTRIES, INC.,
         Individually and as Agent                                           as Borrower

BY:       /s/ CALLI S. HAYES                                        By:      /s/ DONALD J. GUEDRY, JR.
   -----------------------------------------                            -----------------------------------------
         Calli S. Hayes
Title:   Managing Director                                          Title:   Treasurer
      --------------------------------------                              ---------------------------------------

ING (US) CAPITAL CORPORATION,                                       DRILLERS, INC.,
         Individually and as Co-Agent                                        as Borrower

By:      /s/ FRANK FERRARA                                          By:      /s/ DONALD J. GUEDRY, JR.
   -----------------------------------------                            -----------------------------------------

Title:   Senior Associate                                           Title:   Treasurer
      --------------------------------------                              ---------------------------------------

                                                                    DI INTERNATIONAL, INC.,
                                                                             as Guarantor

                                                                    By:      /s/ DONALD J. GUEDRY, JR.
                                                                        -----------------------------------------

                                                                    Title:   Treasurer
                                                                          ---------------------------------------
</TABLE>