spyboat

From spy +‎ boat.

spyboat (plural spyboats)

1. A boat sent to make discoveries and bring intelligence.
   • 1727, John Arbuthnot, Tables of Ancient Coins, Weights and Measures. Explain'd and exemplify'd in several dissertations:

     Mr. Huet thinks that the custom they had of giving the colour of the Sea to the Hulks , Sails and Mariners of their Spy-boats to keep them from being discover'd, came from the Veneti

• “spyboat”, in Webster’s Revised Unabridged Dictionary, Springfield, Mass.: G. & C. Merriam, 1913, →OCLC.