Yes. Saltwater corrosion is brutal on metal, and we weld plenty of saltwater-exposed equipment in the Pacific Northwest. Aluminum holds up well, stainless holds up well, and galvanized hardware on docks and ramps gets repaired with proper post-weld treatment.
For long-term durability in saltwater, the welder selection, the filler material, and the post-weld finish all matter. We pick the right combination for the conditions.