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The Cristobal on the 24 cents, at the time of the issue, belonged to the Panama Railroad (Steamships Management).
The Cristobal was formerly the Tremont of the Boston Steamship Company, having been built in 1902 by the Maryland Steel Company at Sparrow Point, Maryland. A twin-screw vessel of 9,606 gross tons on dimensions 489.Sft. x 58ft. x 28.9ft, she took part in the building of the canal, carrying cargoes of cement and other building materials, and bringing workmen from New York to Panama. She is worthy of special note as she was the first ship to pass through the canal. In October 1940 she was sold to the Permanente Company, Oakland, California, and renamed Philippa. After the Second World War she passed to the Pan-Hellenic Shipping and Trading Company and trans¬ferred to Panamanian registry under the name of Esmeralda.
Sea Breezes 12/53 SG180

1946 Sold to Pan-Hellenic Shipping & Trading Co., Panama as the PHILIPPA.
1948 Sold to Cia de Nav. Mary-Louise SA, Panama not renamed.
1949 Sold to La Florida Cia di Nav. SA, Panama not renamed.
1950 Sold to Cia de Nav. Penomone, Panama, renamed in ESMERALDA.
May 1951 arrived Bari, Italy and was scrapped by Michele Scianatico work of scrapping commenced on October 1951.

She was a sister of the ANCON depict on many stamps.

Source: http://www.miramarshipindex.org.nz