Fishing reels require specialized waterproof greases that can withstand both freshwater and saltwater exposure. Standard oils would quickly wash away or emulsify when exposed to water, leading to corrosion and grinding metal parts. Saltwater anglers must re-grease their reels more frequently because salt crystals can form inside the mechanism, acting like sandpaper on delicate gears. A well-maintained reel can last decades, while a neglected one might fail after a single season.