My poor attempt at a tongue-twister is simply used to mention three words with a common origin.
While its ultimate etymology is unknown, the word ship comes to us from common Germanic words for "ship". To name a few: in Old English, scip; Old Frisian, skip or schip; Old Saxon & Norse, skip; Middle Low German, schip or schêp; Middle Dutch, sc(h)ip or sc(h)eep; etc. Skipper was adapted from the Middle Low German or Middle Dutch form.
The history of the word equip takes some more explaining. The French word in the sense "to equip" is not recorded before the 16th century, but the existence of similar, earlier words in Anglo-French (eskipeson, "equipment", 14th c.) and medieval Latin (eskipare, ésquipare, eschipare, "to man a vessel", 13th c.) indicates older usage, probably originating from the Old Norse skipa, "to man a vessel". John Baret's Alvearie or Quadruple Dictionarie of 1580 lists the intermediate esquippe, defined as "to furnish ships with all ablements."
As for the transformation from esq- to eq-, Francis Junius (Etymologicum Anglicanum) and others cite the habitual French absorption of the s, for example: scribere became écrire; and the French words for "strange" (étrange) and "state" (état).
On a side note: Over the centuries, the shipping lexicon has amassed a large number of terms, as is apparent in this diagram of warships from Ephraim Chambers's Cyclopaedia (1728):
- various entries. Oxford English Dictionary. Second Edition, 1989. Retrieved 2007-06-26.
- F. S. R. "Etymology Of 'Equip.'" Letters to the Editor. The Times Tuesday, Nov 24, 1863; pg. 5; Issue 24724; col D.