Ocean marine insurance is sometimes referred to as "wet" Marine Insurance. Since Ocean marine insurance is designed for property transported by water it would seem to make sense that Inland Marine Insurance would apply to goods and property transported by land and could be called "dry" Marine Insurance. That is accurate enough but not nearly a complete description of Inland Marine Insurance.
Inland Marine policies cover a range of situations and property. In the same way that Ocean Marine provides insurance for the instrumentality of water borne transport, the ship, Inland Marine provides insurance for various instrumentalities of land transportation like bridges and tunnels.
Less obvious is that Inland Marine policies are used to insure instrumentalities of communication like transmission towers. Even more arcane is the notion that Inland Marine policies are used to cover property whose value, use and very condition are under constant change. Examples of property whose value change are schedules of tools, jewelry, furs or other valuable property. For property with constantly changing use consider construction equipment that is used on jobs at different locations subject to different conditions of land and weather. Finally, the condition of buildings and materials under construction change by definition as construction moves from start to completion. All this property and these situations are typically insured under an Inland Marine policy.
Here is a partial list of less obvious kinds of Inland Marine coverage: Accounts Receivable Insurance, Installment Insurance, Installation Insurance, Equipment Floaters Insurance, Valuable Records Insurance (Papers), Consignment Insurance and Parcel Post Insurance. The list is not all inclusive but does give you a good idea how inadequate it is to think of Inland Marine as simply "dry" Marine Insurance.
Typical causes of loss, or perils, insured against on an Inland Marine policy include fire, lightning, windstorm, flood, earthquake, landslide, theft, collision, derailment, overturn of the transporting vehicle, and collapse of bridges.