UNITED STATES
                 SECURITIES AND EXCHANGE COMMISSION
                        Washington, DC 20549

                            SCHEDULE 13G
            Under the Securities and Exchange Act of 1934


              Navios Maritime Midstream Partners LP
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                         (Name of Issuer)

          Common Units Representing Limited Partner Interests
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                  (Title of Class of Securities)

                             Y62134104
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                          (CUSIP Number)

                        November 30, 2014
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    (Date of Event Which Requires Filing of this Statement)

Check the appropriate box to designate the rule pursuant to
which this Schedule is filed:

          [X]     Rule 13d-1 (b)
          [ ]     Rule 13d-1 (c)
          [ ]     Rule 13d-1 (d)

* The remainder of this cover page shall be filled out for a
reporting person's initial filing on this form with respect to
the subject class of securities, and for any subsequent amendment
containing information which would alter the disclosures provided
in a prior cover page.

The information required in the remainder of this cover page
shall not be deemed to be "filed" for the purpose of Section 18
of the Securities Exchange Act of 1934 ("Act") or otherwise
subject to the liabilities of that section of the Act, but shall
be subject to all other provisions of the Act (however, see
the Notes.)


CUSIP NO. Y62134104   13G


1     Name of Reporting Person / IRS Identification Number:
      Piper Jaffray Companies / 30-0168701

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2     Check the Appropriate Box if a Member of a Group    (a)  [ ]
      			                                  (b)  [ ]

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3     SEC Use Only

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4     Citizenship or Place of Organization
      Delaware

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   Number of
                   5     Sole Voting Power
    Shares               0 Shares
                   -----------------------------------------------
 Beneficially
                   6     Shared Voting Power
   Owned By              1,400,000 Shares
                   -----------------------------------------------
     Each
                   7     Sole Dispositive Power
   Reporting             0 Shares
                   -----------------------------------------------
    Person
                   8     Shared Dispositive Power
     With                1,400,000 Shares
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9     Aggregate Amount Beneficially Owned by Each Reporting Person
      1,400,000 Common Units  (See Exhibit A)

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10    Check if the Aggregate Amount in Row (9) Excludes Certain
      Shares  [ ]

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11    Percent of Class Represented by Amount in Row (9)
      15%

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12    Type of Reporting Person
      HC

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Item 1     (a)  Name of Issuer: Navios Maritime Midstream Partners L.P.
Item 1     (b)  Name of Issuer's Principal Executive Offices:
                7 Avenue De Grande Bretagne Office 11B2
		Monte Carlo 09 98000

Item 2     (a)  Person Filing: Piper Jaffray Companies
Item 2     (b)  Address: 800 Nicollet Mall Suite 800
                         Minneapolis, MN 55402

Item 2     (c)  Citizenship: Piper Jaffray Companies is a
                             Delaware Corporation

Item 2     (d)  Title of Class of Securities: Common Units Representing
                Limited Partner Interests

Item 2     (e)  CUSIP Number: Y62134104

Item 3     This statement is filed pursuant to Rule 13d-1(b) or
           13d-2(b) and the person filing, Piper Jaffray Companies,
           is a parent holding company in accordance with Section
           240.13d-1(b)(ii)(G). (Note: See Item 7).

Item 4     Ownership

           (a)  Amount Beneficially Owned:
                Advisory Research, Inc.    1,400,000 Shares

           (b)  Percent of Class           15%

           (c)  Number of common units as to which reporting person has:
                (i)    Sole Voting Power        0          Shares
                (ii)   Shared Voting Power      1,400,000  Shares
                (iii)  Sole Dispositive Power   0          Shares
                (iv)   Shared Dispositive Power 1,400,000  Shares

           Advisory Research acts as an investment adviser to certain
           investment companies registered under the Investment Company
           Act of 1940. ARI by virtue of investment advisory agreements
           with these investment companies, has all investment and
	   voting power over the common units owned of record by these
           investment companies. However, despite their delegation of
           investment and voting power to ARI, these investment companies
           may be deemed to be the beneficial owners under Rule 13d-3
           of the Act, of the common units they own of record because
           they have the right to acquire investment and voting power
           through termination of their investment advisory agreement
           with ARI. Thus, ARI has reported that it shares voting power
           and dispositive power over the common units owned of record
           by these investment companies.

Item 5     Ownership of Five Percent or Less of a Class:
           Not Applicable.

Item 6     Ownership of More than Five Percent on Behalf of Another
	   Person:  The Investment Companies ARI manages have the
	   right to receive or the power to direct the receipt of
	   dividends from, or the proceeds from the sale of the
	   common units held in their respective accounts. Except for
           the Nuveen Energy MLP Total Return Fund and the Fiduciary/
	   Claymore MLP Opportunity Fund, no Investment Companies'
           interest exceeds 5% of the class of securities.

Item 7     Identification and Classification of the Subsidiary
           Which Acquired the Security being Reported on by the
           Parent Holding Company:

           See attached Exhibit A.

Item 8     Identification and Classification if Members of
           the Group:  Not Applicable

Item 9     Notice of Dissolution of Group:  Not Applicable

Item 10    Certification

           By signing below I certify that, to the best of my
           knowledge and belief, the securities referred to
           above were acquired and are held in the ordinary
           course of business and were not acquired and are
           not held for the purpose of or with the effect of
           changing or influencing the control of the issuer
           of such securities and were not acquired and are
           not held in connection with or as a participant
           in any transaction having such purposes or effect.

			SIGNATURE

After reasonable inquiry and to the best of my knowledge and
belief, I certify that the information set forth in this
statement is true, complete and correct.

			12/10/2014
			----------------------------------
			Date

			Piper Jaffray Companies

			By /s/ Christopher D. Crawshaw
			----------------------------------
			Signature

			Christopher D. Crawshaw
			Head of Asset Management
			----------------------------------
			Name/Title


			Advisory Research, Inc.

			By /s/ Christopher D. Crawshaw
			----------------------------------
			Signature

			Christopher D. Crawshaw
			President, Chief Executive Officer
			----------------------------------
			Name/Title



              JOINT FILING AGREEMENT

The undersigned persons, on December 10, 2014, agree and consent
to the joint filing on their behalf of this Schedule 13G
in connection with their beneficial ownership of the Common
Units of Navios Maritime Midstream Partners LP at November 30, 2014.


			Piper Jaffray Companies

			By /s/ Christopher D. Crawshaw
			----------------------------------
			Signature

			Christopher D. Crawshaw
			Head of Asset Management
			----------------------------------
			Name/Title


			Advisory Research, Inc.

			By /s/ Christopher D. Crawshaw
			----------------------------------
			Signature

			Christopher D. Crawshaw
			President, Chief Executive Officer
			----------------------------------
			Name/Title



                       EXHIBIT A

Pursuant to the instructions in Item 7 of Schedule 13G, Advisory
Research, Inc. ("ARI"), 180 N. Stetson, Chicago, IL 60601, a
wholly-owned subsidiary of Piper Jaffray Companies and an
investment adviser registered under Section 203 of the
Investment Advisers Act of 1940, is the beneficial owner of
1,400,000 common units or 15% of the Common Units outstanding
of Navios Maritime Midstream Partners LP ("the Company") as a
result of acting as investment adviser to various clients.

Piper Jaffray Companies may be deemed to be the beneficial owner
of these 1,400,000 common units through control of ARI.  However, Piper
Jaffray Companies disclaims beneficial ownership of such common units.
In addition, the filing of this Schedule 13G shall not be construed
as an admission that the reporting person or any of its affiliates
is the beneficial owner of any securities covered by this Schedule
13G for any other purposes than Section 13(d) of the Securities
Exchange Act of 1934.