Krakatoa

In Civ 5 Krakatoa appeared near the cost so that I was able to settle on the coast and have control of the volcano. My question is how do I work the volcano for the research; I have tried a work boat and embarked workers but cannot figure it out.

Just like you work any other tile - with the Citizen Management controls from the city that you wish to work Krakatoa from. Mind you that no tile may be more than 3 tiles from the city you intend to work it in. As long as it's within that range, go to the city screen -> Citizen Management -> Manual -> click on the tile to select it.

You don't need work boats or workers because Krakatoa is not a resource, it's a terrain feature. Two different things - and in fact, unless you're running a DLL mod, since all natural wonders qualify as mountains in that they're impassable, you shouldn't be able to get either unit on Krakatoa to improve it.

You need to have the tile of the volcano within 3 tile distance from any of your cities and within your borders. Then go into the city and lock a citizen there.

Just wanted to mention that there is simple mod in the steamworkshop to improve the placement of krakatoa nearer to shores....so it no longer shows up in the middle of the ocean without some landmass nearby.