The first is something similar to the charcoal burning in Ark. Something the burns wood quickly to produce large amounts of charcoal. I was thinking of a bonfire, a scaled up cooking fire both in terms of size, resources required and charcoal production rate.

The second is a small sail boat that either replaces the dingy, uses something like the cargo rack (with the same impacts in terms of speed) or can be towed. Something that has room for a half dozen players and maybe a couple of storage chests. So you can ferry people and resources between you bigger ships without having to swim. Ideal for visiting cold islands and hauling back the loot.