You cannot patent selecting hooks based on observing water conditions
In April 2020, the Court of Appeals for the Federal Circuit held that a patent applicant's claimed method for improved fishing was not patentable (see In re: Rudy, Case 2019-2301 (April 24, 2020), stored on Mega.nz).
The claim on appeal was:
34. A method for fishing comprising steps of (1) observing clarity of water to be fished to determine whether the water is clear, stained, or muddy, (2) measuring light transmittance at a depth in the water where a fishing hook is to be placed, and then (3) selecting a colored or colorless quality of the fishing hook to be used by matching the observed water conditions ((1) and (2)) with a color or colorless less quality which has been previously determined to be less attractive under said conditions than those pointed out by the following correlation for fish-attractive non-fluorescent colors: [based on a table]
The Federal Circuit found that this claim was directed to an abstract idea of "selecting a fishing hook based on the observed water conditions" (Opinion at 7).
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