Firefly Rod

Waveborne in the Second Sea sells Firefly Rod, and unlike most Fisch rods it is bought with a different currency: 9,500E$, not C$. The wiki describes a rod humming with energy and a line that glows like a trail of fireflies, with a claim that the faster you reel, the brighter it shines.

Its numbers lean toward speed. Lure Speed 85 is 57th of 184 obtainable rods, Resilience 25 is 62nd of 184, and the 175 kg weight cap is 104th of 117 rods that list one. Luck of 55 is 155th of 184 and Control of -0.01 is 163rd of 185, so it is not built for rare fish or for a calm bar. It also carries a passive; the wiki does not spell out the effect beyond the glow.

The weight cap is the biggest warning: 175 kg means large fish will be out of reach. Use it for quick cycles on small and medium catches, and expect to lose the heaviest ones.

It makes sense as a way to spend E$ you have no better use for, especially if you enjoy the visual. For a serious hunt for rarities, a rod with higher Luck and a larger cap is the better pick, and the E$ will go further elsewhere.