United States securities and exchange commission logo





                              April 22, 2022

       Eli Spiro
       Chairman and Chief Executive Officer
       CleanTech Acquisition Corp.
       207 West 25th Street, 9th Floor
       New York, NY 10001

                                                        Re: Cleantech
Acquisition Corp.
                                                            Amendment No. 1 to
Registration Statement on Form S-4
                                                            Filed March 31,
2022
                                                            File No. 333-262431

       Dear Mr. Spiro:

             We have reviewed your amended registration statement and have the
following
       comments. In some of our comments, we may ask you to provide us with
information so we
       may better understand your disclosure.

              Please respond to this letter by amending your registration
statement and providing the
       requested information. If you do not believe our comments apply to your
facts and
       circumstances or do not believe an amendment is appropriate, please tell
us why in your
       response.

              After reviewing any amendment to your registration statement and
the information you
       provide in response to these comments, we may have additional comments.
Unless we note
       otherwise, our references to prior comments are to comments in our March
1, 2022 letter.

       Amendment No. 1 to Registration Statement on Form S-4

       Cover Page

   1.                                                   Please revise here, and
elsewhere throughout the filing where you discuss the Securities
                                                        Purchase Agreement, to
ensure the exercise price of the associated warrants is consistently
                                                        disclosed and to
clarify what is meant by the statement that this debt financing is "subject
                                                        to adjustment."
       Q: Did the CLAQ Board obtain a fairness opinion in determining whether
or not to proceed with
       the Business Combination?, page 8

   2.                                                   Revise to reconcile
your disclosure that the CLAQ Board obtained a fairness opinion from
                                                        Duff & Phelps "in
connection with its determination to approve the Business
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FirstName
CleanTech LastNameEli    Spiro
            Acquisition Corp.
Comapany
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         Combination" given that the Board approved the merger before obtaining
the fairness
         opinion. Revise to disclose why the CLAQ Board decided to obtain a
fairness opinion,
         and explain why the Board obtained the fairness opinion only after
approving the merger.
3.       Prominently disclose that the fairness opinion addresses only the
fairness of
         the consideration to be paid by CLAQ to the Nauticus security holders
in the Business
         Combination. Highlight that Duff & Phelps opines only on fairness to
CLAQ, as opposed
         to the public shareholders or shareholders unaffiliated with the
sponsors or affiliates
         thereof.
Q: How will the Initial Stockholders vote?, page 9

4.       We note your response to prior comment 4. Clarify what percentage of
outstanding shares
         of common stock entitled to vote held by your directors, executive
officers and their
         affiliates is represented by the approximately 20.0% subject to the
Letter Agreement.
Q: Do any of CLAQ's directors or officers have interests that may conflict with
my interests with
respect to the Business Combination?, page 11

5.       We note your response to prior comment 5. However, your revisions do
not appear to
         disclose the amount of what the sponsors and their affiliates have at
risk in the
         "aggregate." Advise or revise to disclose the aggregate dollar amount
of what the
         sponsors and their affiliates have at risk that depends on completion
of a business
         combination. Include the current value of securities held, loans
extended, fees due and
         out-of-pocket expenses for which the sponsors and their affiliates are
awaiting
         reimbursement. Provide similar disclosure for the company   s officers
and directors, if
         material.
6.       We note your response to prior comment 31, and reissue our comment in
part.
         Disclose the aggregate fees payable to Chardan that are contingent
upon completion of the
         business combination. We note your disclosure on page 99 that Chardan
is an affiliate of
         CleanTech Investments, one of your co-sponsors. To the extent Chardan
is an affiliate of
         the sponsors, please include the aggregate fees payable to Chardan
along with your
         disclosure of the aggregate fees owed to the sponsors and their
affiliates.
Service and Revenue, page 23

7.       We note your response to prior comment 12 and your statement on page
107 that Nauticus
         has made some sales to operate devices although not "precisely"
through its RaaS model.
         Please clarify this statement. Additionally, provide a breakdown of
revenue in the
         summary of your prospectus/proxy statement that shows the revenues
Nauticus generates
         from services and those from direct product sales. Clarify the nature
of the revenue
         disclosed as generated from services if it is not currently generated
from Nauticus' RaaS
         model. Clearly state whether a customer could subscribe to the RaaS
business model at
         present or when this subscription service will be available. Clarify
whether your
         statement on page 23 that "we anticipate that the initial services
will be paid through
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FirstName
CleanTech LastNameEli    Spiro
            Acquisition Corp.
Comapany
April       NameCleanTech Acquisition Corp.
       22, 2022
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         conventional contracting methods, directly with the customer or in
regional partnerships
         with an in-country service entity" means that such services will not
be part of your RaaS
         business model.
Securities Purchase Agreement, page 27

8.       We note that the Debt Financing portion of your PIPE Investment is
dependent upon the
         hiring of a chief financial officer with public company experience and
the raising of
         $25,000,000 in additional equity financing. Disclose on your cover
page that
         the consummation of the Debt Financing is contingent upon these
conditions
         precedent. Additionally, advise as to the status of these conditions
precedent and whether
         your Equity Financing satisfies the requirement for Concurrent
Financing in your
         Securities Purchase Agreement. To the extent these conditions
precedent have not been
         met, disclose the risk that the minimum cash condition contained in
the Merger
         Agreement may not be satisfied without the Debt Financing depending on
the number of
         CLAQ public stockholders who seek redemption, among other things.
Ownership of the Post-Business Combination Company After the Closing, page 30

9.       We note your disclosure of certain letter agreements entered into
between February and
         March 2022 with three different investment banks for capital market
advisory services.
         Disclose the counterparties   including whether CLAQ or Nauticus or
both parties entered
         into these agreements   and the fees associated with each letter
agreement. Clarify the
         purpose of these engagements and any key terms, including which of the
three agreements
         includes the Residual Period. Tell us why these services were sought
at this time and file
         a copy of any related material agreement or advise why this is not
required. Refer to Item
         601(b)(10) of Regulation S-K.
Background of the Business Combination, page 96

10.      We note your response to prior comment 25 and your disclosure on page
95 that CLAQ's
         CEO will be a member of the board of directors of the combined company
upon closing
         pursuant to the Director Nomination Agreement. Disclose in your
Background of the
         Business Combination whether there were any discussions about this
role or nomination
         agreement or any other discussions involving continuing employment or
involvement for
         any persons affiliated with CLAQ before the merger.
Certain Nauticus' Projected Financial Information, page 106

11.      We note your response to prior comment 29, and reissue our comment in
part. Disclose
         any material information and figures the CLAQ Board considered about
Nauticus'
         publicly traded company peer set when performing its comparison.
12.      Provide us with the legal basis for the parties' disclaimer on page
107 of any obligations to
         update or revise, or publicly disclose any update or revision to the
projections "even in the
         event that any or all of the assumptions underlying the projections
are shown to be in error
 Eli Spiro
FirstName
CleanTech LastNameEli    Spiro
            Acquisition Corp.
Comapany
April       NameCleanTech Acquisition Corp.
       22, 2022
April 422, 2022 Page 4
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FirstName LastName
         or change." Refer generally to Item 10(b)(3)(iii) of Regulation S-K.
Interests of Certain Persons in the Business Combination, page 109

13.      We note your response to prior comment 30, and reissue our comment in
part. Revise the
         conflicts of interest discussion to highlight any fiduciary or
contractual obligations to
         other entities held by the sponsor or its affiliates. Additionally,
clarify how the board
         considered those conflicts in negotiating and recommending the
business combination.
Material U.S. Federal Income Tax Consequences, page 134

14.      We note your response to prior comment 33, and reissue our comment in
part. Given your
         disclosure of the parties' intention for the merger to qualify as a
reorganization    within
         the meaning of Section 368(a) of the Internal Revenue Code, revise to
include counsel's
         tax opinion as an exhibit as required by Item 601(b)(8) of Regulation
S-K. Additionally,
         to the extent there is uncertainty as to whether the merger will
qualify as a tax-free
         reorganization, provide corresponding risk factor disclosure.
Management's Discussion and Analysis of Financial Condition and Results of
Operations of
CLAQ
Liquidity and Capital Resources, page 142

15.      Please revise to disclose that CLAQ is a going concern and address any
factors related to
         this fact that may impact liquidity, cash flow needs and/or capital
resources over the next
         12-months. Ensure your disclosures address the fact that CLAQ must
complete a business
         combination prior to July 19, 2022 or be required to liquidate. Refer
to Item 303(b)(1) of
         Regulation S-K.
Customers, page 156

16.      We note your disclosure about a Collaboration Agreement with a third
party that Nauticus
         plans to leverage to pursue business opportunities. Revise to disclose
the duration and key
         terms of this agreement and file a copy as an exhibit to your
registration statement or tell
         us why this is not required. Refer to Item 601(b)(10) of Regulation
S-K.
Management's Discussion and Analysis of Financial Condition and Results of
Operations of
Nauticus
Results of Operations, page 164

17.      Please revise to explain why cost of revenue exceeded revenue in
fiscal year 2020, and
         how this trend reversed in fiscal year 2021.
Unaudited Pro Forma Condensed Combined and Consolidated Financial Information
Description of the Business Combination, page 174

18.      We note that the Securities Purchase Agreement (Debt Financing) is
conditioned upon
         meeting three criteria, one of which includes raising $25 million in
equity financing from
 Eli Spiro
CleanTech Acquisition Corp.
April 22, 2022
Page 5
         strategic investors. Please revise to clarify whether the Subscription
Agreement (Equity
         Financing) entered into on December 14, 2021 satisfies the $25 million
equity financing
         condition. Alternatively, revise to address how you intend to meet the
Minimum Cash
         Condition threshold of $50 million if the conditions required for the
Debt Financing are
         not met such that you do not receive the estimated $37.2 million in
proceeds from such
         financing.
Notes to Unaudited Pro Forma Condensed Combined and Consolidated Financial
Information
Note 3. Adjustments to Unaudited Pro Forma Condensed Combined and Consolidated
Financial
Information, page 179

19.      Please revise to explain how you calculated the transaction expenses
in pro forma
         adjustment (C) of $21.7 million, specifically quantifying each
component included within
         this amount. Also, it appears the $100,000 adjustment to accounts
payable relates to pro
         forma adjustment (C). If true, revise to indicate as such in the pro
forma balance sheet
         and include a discussion of this adjustment in the pro forma footnote.
Refer to Rule 11-
         02(a)(8) of Regulation S-X.
20.      It appears pro forma adjustment (E) is mismarked on the face of your
pro forma balance
         sheet. In this regard, this adjustment relates to the conversion of
the $10.25 million
         convertible notes payable within current liabilities; however, you
have instead eliminated
         the long-term RCB term loan for $14.7 million. Also, it appears that
the common stock
         adjustment does not agree with the 5,299,543 common shares, par value
$0.0001, that will
         be issued upon conversion of such notes and, similarly, neither does
your APIC
         adjustment (E). Lastly, tell us how the interest expense adjustment
related to these notes
         is reflected within accumulated deficit. Please revise accordingly.
21.      We note that pro forma adjustment (I) reflects both the cash proceeds
from, and the
         issuance of, the $15 million RCB term loan; however, this loan was
received in December
         2021 and appears to already be reflected in Nauticus' December 31,
2021 historical
         balance sheet. Please revise or advise. Additionally, revise to
include a pro forma income
         statement adjustment to eliminate the related interest expense and
debt discount
         amortization on this loan.
22.      Please tell us how the interest expense and amortization of debt
discount included in
         adjustment (DD) is reflected in the pro forma balance sheet
adjustments. In this regard, it
         is unclear how you reflected this expense in accumulated deficit.
Related Party Loans, page 220

23.    We note your response to prior comment 48. Please advise why Chardan
Capital Markets,
FirstName LastNameEli Spiro
       LLC is listed as a potential loan party and disclose if it has loaned
funds to CLAQ since
Comapany    NameCleanTech
       the beginning          Acquisition
                      of the last fiscal yearCorp.
                                              or whether there are outstanding
borrowings. Refer to
       Item 404(a) of
April 22, 2022 Page 5  Regulation   S-K.
FirstName LastName
 Eli Spiro
FirstName
CleanTech LastNameEli    Spiro
            Acquisition Corp.
Comapany
April       NameCleanTech Acquisition Corp.
       22, 2022
April 622, 2022 Page 6
Page
FirstName LastName
Nauticus Related Party Transactions, page 222

24.      We note your response to prior comment 49 and your disclosure that
Nauticus sold seven
         HaloGuard systems to Transocean. Provide the approximate dollar value
of the amount
         involved in this transaction. Refer to Item 404(a)(3) of Regulation
S-K.
CleanTech Acquisition Corp. Notes to Consolidated Financial Statements
Note 1. Description of Organization and Business Operations
Earnout Shares, page F-10

25.      Please revise here to describe each of the three "triggering events"
thresholds for your
         Earnout shares, similar to your revised disclosures elsewhere in
response to prior
         comment 1. Similar revisions should be made to the introductory
paragraphs to your
         unaudited pro forma financial statements.
Note 11. Subsequent Events, page F-27

26.      We note your disclosure of the advisory services fees that will be
payable upon the
         business combination to two separate investment banks in the aggregate
amount of
         $700,000. Per disclosures elsewhere in the filing, it appears that
advisory fees totaling
         $2.45 million will be paid to three investment banks upon closing this
transaction. Please
         revise, either here or in Note 13 to Nauticus' financial statements,
to include a discussion
         of the third advisory agreement. Refer to ASC 855-10-50-2.
Nauticus Robotics, Inc. Notes to Financial Statements
Note 2. Summary of Significant Accounting Policies
Revenue Recognition, page F-35

27.      We note your revised disclosures and response to prior comment 50.
Please revise your
         Product and Services disclosure on page 165 to include information
related to your
         HaloGuard product, such as a description of this product, the typical
contract terms, etc.
         Also, address whether you intend to phase-out this product as you
continue to develop and
         sell your core robotics products. In addition, revise here to clarify
the performance
         obligations included in these product sales. In this regard, clarify
whether such products
         include any ongoing services, such as technology updates or customer
service
         arrangements, and describe further your accounting for such product
sales. Lastly, revise
         to address when you consider "title and risk of loss" to have passed
onto your customers
         for your product sales. In this regard, address whether this occurs
upon delivery or at
         some other point in time, and how you account for shipping and
delivery expenses. Refer
         to guidance in ASC 606-10-25-18A and 25-18B.
28.      You state that you generate revenue from designing and developing
subsea robots
         and software and providing related engineering, technical and other
services according to
         customer specifications, which you appear to classify as service
revenues. In addition,
         you state that products and services are typically not distinct within
a contract and are,
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CleanTech LastNameEli    Spiro
            Acquisition Corp.
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April 722, 2022 Page 7
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         therefore, considered one performance obligation. Please provide us
with your accounting
         analysis that supports your conclusion that services and products meet
the requirements to
         be considered a single performance obligation. Also, tell us whether
you have sold any
         contracts, to date, that contain multiple performance obligations.
Refer to ASC 606-10-25-
         21.
29.      Please clarify for us your reference throughout the filing to Robotics
as a Service (RaaS).
         In this regard, tell us whether any of your historical revenues have
been generated from
         such arrangements and, if so, tell us which of the contracts discussed
on page 165 are
         RaaS arrangements. Tell us whether these arrangements provide your
customer with
         access to the vehicles and the software platform for a specified term,
and explain how you
         considered whether these are service arrangements under ASC 606 or
leases under ASC
         842. Alternatively, tell us whether the customer takes title to the
vehicles and, if so,
         explain why you consider these to be service arrangements rather than
product sales.
         Also, clarify whether customers are required to purchase any
technology-related
         maintenance or update services in order for the vehicle to continue to
function as intended
         and, if so, how that factors into your accounting. Lastly, tell us how
these
         arrangements are addressed in your current revenue recognition policy
disclosures or
         revise as necessary.
30.      You state that Hydronaut 1 is currently fulfilling charter days for a
large confidential
         government contractor. Please tell us, and revise your disclosures as
necessary to clarify,
         how you account for this arrangement. In your response, explain how
you considered
         whether this arrangement qualifies as a lease pursuant to ASC 842.
31.      We note your revised disclosures and response to prior comment 53. As
previously
         requested, please disclose the amount of any unsatisfied remaining
performance
         obligations as of period end and when you expect to recognize the
revenue, or otherwise
         advise. Refer to ASC 606-10-50-13.
32.      We note from your disclosure on page F-36 that there is $756,666 of
equipment rental
         income included within service revenue related to a lease agreement
that commenced in
         June 2021. Please revise to disclose the applicable information
required by ASC 842-30-
         50, including, but not limited to, the nature and type of the lease,
amounts recognized in
         the financial statements related to the lease, whether the lease
involves a related party,
         tabular disclosure of the operating lease income and a maturity
analysis of the future lease
         payments to be received, as applicable.
Segment Reporting, page F-35

33.      You state that you operate in a single reportable segment because each
revenue stream
         possesses similar production methods, distribution methods and
customer quality and
         consumption characteristics. Please tell us whether you have more than
one operating
         segment and, if so, provide us with a list of your operating segments.
In your
         response, clarify what is meant by each revenue stream and tell us
whether you consider
 Eli Spiro
CleanTech Acquisition Corp.
April 22, 2022
Page 8
      each revenue stream to be a separate operating segment pursuant to ASC
280-10-50-1
      through 50-9. To the extent that you have multiple operating segments,
please tell us how
      you considered the quantitative thresholds in ASC in ASC 280-10-50-12 in
determining
      your reportable segment.
Major Customer and Concentration of Credit Risk, page F-38

34.   We note your revised disclosures in response to prior comment 56 where
you refer to
      sales to "a large confidential government contractor" in both fiscal
years 2021 and 2020.
      Please revise to clarify whether you are referring to the same customer
in each period.
Note 13. Subsequent Events, page F-47

35.   We note your disclosure here related to the two Hydronauts under contract
with Diverse
      Marine Ltd, which you refer to as the Hydronaut 2 and Hydronaut 3.
However, you then
      disclose the purchase prices for the Hydronaut 1 and Hydronaut 2. It
appears from
      disclosures elsewhere in the filing that your initial Hydronaut is
already in service. Please
      revise here to clarify which Hydronauts, e.g., 1, 2 or 3, are under
contract with Diverse
      Marine and the respective purchase prices.
       You may contact Brittany Ebbertt, Senior Staff Accountant, at (202)
551-3572 or
Kathleen Collins, Accounting Branch Chief, at (202) 551-3499 if you have
questions regarding
comments on the financial statements and related matters. Please contact
Patrick Faller, Staff
Attorney, at (202) 551-4438 or Joshua Shainess, Legal Branch Chief, at (202)
551-7951 with any
other questions.



                                                            Sincerely,
FirstName LastNameEli Spiro
                                                            Division of
Corporation Finance
Comapany NameCleanTech Acquisition Corp.
                                                            Office of
Technology
April 22, 2022 Page 8
cc:       Giovanni Caruso
FirstName LastName