What follows is an opinion from a United States Court of Appeals.
Intervenors who participated as parties at the courts of appeals should be counted as either appellants or respondents when it can be determined whose position they supported. For example, if there were two plaintiffs who lost in district court, appealed, and were joined by four intervenors who also asked the court of appeals to reverse the district court, the number of appellants should be coded as six.
When coding the detailed nature of participants, use your personal knowledge about the participants, if you are completely confident of the accuracy of your knowledge, even if the specific information is not in the opinion. For example, if "IBM" is listed as the appellant it could be classified as "clearly national or international in scope" even if the opinion did not indicate the scope of the business. 

Your task concerns the first listed appellant. The nature of this litigant falls into the category "private business (including criminal enterprises)", specifically "transportation". Your task is to determine what subcategory of business best describes this litigant.

Opinion:
PORT ARTHUR SHIPPING CORPORATION and Texas Employers’ Insurance Association, Appellants, v. C. D. CALBECK, Deputy Commissioner, Eighth Compensation District U. S. Department of Labor, Bureau of Employees’ Compensation, et al., Appellees.
No. 18256.
United States Court of Appeals Fifth Circuit.
Feb. 9, 1961.
Carl O. Bue, Jr., Royston, Rayzor &. Cook, Houston, Tex., for appellants.
Herbert P. Miller, Asst. Sol., Alfred H. Meyers, Atty., Dept, of Labor’, Wash-. ington, D. C., Ward Stephenson, Orange Tex., Lloyd W. Perkins, Asst. U. S. Atty., Paul N. Brown, U. S. Atty., Tyler, Tex., Harold C. Nystrom, Acting Sol., Dept, of Labor, Washington, D. C., for appellees.
Before TUTTLE, Chief Judge, HUTCHESON, Circuit Judge, and CLAYTON, District Judge.
PER CURIAM.
The employer of this deceased longshoreman here attacks the decision of the Deputy Commissioner of the United States Bureau of Employees’ Compensation finding that one Beatrice was the widow of Eli Mason, the longshoreman within the definition of the Act, 33 U.S.C.A. § 902(16).
We conclude that the evidence before the Deputy Commissioner warranted his finding that the “conjugal nexus between the claimant and the decedent (was) subsisting at the time of the latter’s death.” See Thompson v. Lawson, 347 U.S. 334, 336, 74 S.Ct. 555, 557, 98 L.Ed. 733.
Here the decedent continued to furnish support for Beatrice and he treated her as an object of his concern, even though he had technically deserted her. The fact that she found other fleeting but impermanent domestic attachments did not prevent her from meeting the requirement of the Act which, as construed by the Supreme Court, is “that she must continue to live as the deserted wife of the (decedent).”
The judgment is affirmed.

Question: This question concerns the first listed appellant. The nature of this litigant falls into the category "private business (including criminal enterprises)", specifically "transportation". What subcategory of business best describes this litigant?

Choices:
railroad
boat, shipping
shipping freight, UPS, flying tigers
airline
truck, armored cars
other
unclear

Answer: 1