smithcraft n.

Middle English smith, from Old English smið "blacksmith, armorer, one who works in metal" (jewelers as well as blacksmiths), more broadly, "handicraftsman, practitioner of skilled manual arts" (also including carpenters), from Proto-Germanic *smithaz "skilled worker" (source also of Old Saxon smith, Old Norse smiðr, Danish smed, Old Frisian smith, Old High German smid, German Schmied, Gothic -smiþa, in aiza-smiþa "coppersmith"), from a suffixed form of PIE root *smi- "to cut, work with a sharp instrument" (source also of Greek smilē "knife for cutting and carving, chisel").

Attested as a surname by c. 975. Also used in a Middle English psalter of God, when he created light. Other common surnames meaning "smith" include Ferraro (Italian), Haddad (Arabic), Kovács (Hungarian, a Slavic loan-word), Kowalski (Polish), Herrero (Spanish), Kuznets (Russian), MacGowan (Irish, "son of the blacksmith").

Old English cræft (West Saxon, Northumbrian), -creft (Kentish), "power, physical strength, might," from Proto-Germanic *krab-/*kraf- (source also of Old Frisian kreft, Old High German chraft, German Kraft "strength, skill;" Old Norse kraptr "strength, virtue"). The ultimate etymology is uncertain.

Sense expanded in Old English to include "skill, dexterity; art, science, talent" (via a notion of "mental power"), which led by late Old English to the meaning "trade, handicraft, employment requiring special skill or dexterity," also "something built or made." The word still was used for "might, power" in Middle English.

Use for "small boat" is first recorded 1670s, probably from a phrase similar to vessels of small craft and referring either to the trade they did or the seamanship they required, or perhaps it preserves the word in its original sense of "power."