  Rare-earth delafossites were recently proposed as promising candidates for
the realization of an effective $S$=1/2 quantum spin liquid (QSL) on the
triangular lattice. In contrast to the most actively studied triangular-lattice
antiferromagnet YbMgGaO$_4$, which is known for considerable structural
disorder due to site intermixing, NaYbS$_2$ delafossite realizes structurally
ideal triangular layers. We present detailed $\mu$SR studies on this regular
(undistorted) triangular Yb sublattice based system with effective spin
$J_{\mathrm{eff}}=1/2$ in the temperature range 0.05 - 40 K. Zero-field (ZF)
and longitudinal field (LF) $\mu$SR studies confirm the absence of any long
range magnetic order state down to 0.05K ($\sim J$/80). Current $\mu$SR results
together with the so far available bulk characterization data suggest that
NaYbS$_2$ is an ideal candidate to identify QSL ground state.
