wrap mesh around other meshes (like a skin) I have a imported character and its fairly detailed and I am using fluid sims and fluid anomaly happen when body moves,
I have tested the fluid sim on spheres and icos and no problems...

Can someone give me ideas of how I should seal all gaps/holes(blanket the mesh)
I have tried the following,
Using constraint location of character head, adding a sphere in areas that fluid disappears or leaks.. 
its alot of work but it does the job

I am looking for a simple way to create a skin tight blanket around the entire mesh for the fluid to better simulate. I can do this manually by moving mesh around but its difficult.

Skin Modifier does not work, maybe object is too detailed to skin, it does nothing and appears to freeze blender.. im sure if I leave it for hours it might complete?!

Cheers
Blender does not have automated skinning tools to make a wrapped mesh around other (intersecting/non-manifold/etc..) meshes.

You want to voxelize such meshes, add all the volumes together and turn the volume back to a mesh. You will find this functionality in programs like Zbrush or Houdini.

In Blender there are 2 workarounds:


use metaballs as dupliverts for the mesh vertices. This will create an inflated representation of the mesh (based on the metaball size) that is a single water-tight surface (if the metaballs are big enough so there are no holes). The denser the geometry, the smaller the metaballs can be and the smaller the inflation. Convert metaballs to mesh and then you can shrink the mesh to maintain the original volume. However this results in the surface being smoothed.
use CubeSurfer addon - similar functionality as metaballs. Since metaballs were optimized performance-wise, this is in most cases slower to compute.


There is also the possibility to manually retopologize all the meshes together. A shrinkwrap modifier can help with wrapping this created skin mesh around surfaces.

You can also edit all the pieces to be water-tight and manifold and then use Blender's booleans to unify them together.