The Finsulate Lakegrade variant was developed mainly for freshwater areas, with occasional stays in salt waters. Here, the biggest challenge is to prevent the on-growth of mussels and algae. And in (mountain) lakes, accumulation of chalk was another impact factor to consider. The Lakegrade version will prevent most of these types of on-growth. And in cases where you do find some on-growth on the hull, just brush it off or apply some high pressure water.
The Lakegrade variant would also be our recommendation if you plan to cruise occasionally in salt water, too, for several weeks at a time.