According to the latest information available, the boat ramp named Mississippi River -- Lakeview Marina and Bar Boat Access in Iowa is a concrete boat ramp. It has a width of 20 feet, which makes it suitable for launching boats of different sizes. This particular boat ramp services the Mississippi River, which is a significant water body in the United States, spanning across multiple states.

As far as the type of craft that are permitted on the water, it seems that there are no specific restrictions mentioned on the official website of the Iowa Department of Natural Resources. However, it is advisable to check with local authorities or the marina operating the boat ramp for any specific guidelines or restrictions.

In summary, the Mississippi River -- Lakeview Marina and Bar Boat Access is a concrete boat ramp in Iowa that is 20 feet wide and services the Mississippi River. While there are no specific restrictions mentioned on the official website, it is best to confirm with local authorities or the marina for any specific guidelines or restrictions regarding the type of craft permitted on the water.