Here is the next installment in my RTFM exercise
The OM-D E-M1 ii, and I expect other Oly mirrorless models, has a 'Preset MF' function that drives the lens to a preset distance and switches to manual focus. What I hadn't appreciated until now, and what I hadn't read anywhere, is that you can set the Preset distance to ZERO. By doing that ANY autofocus lens is driven to whatever its shortest focus distance is. I tried it with the 60mm F2.8 macro, 25mm F1.8 prime, and 12-50mm power-zoom kit lens. Note: with the zoom lens you have to first set the zoom because its mimimum focus distance changes as you zoom.
This is great for macro photography and basically any underwater situation where you have a small stationary subject that isn't shy. Simply trigger Preset MF, approach the subject till it is in focus and get the picture with maximum magnification and the least amount of water between it and the lens. To make this even easier you can program one of the camera buttons to trigger Preset MF. The example below assigns the Fn2 button to do so.
Menu>gear>B>Button Function>Fn2 Function>Preset MF
To set the preset distance to zero use the following menu to change the default (focus at infinity) to zero.
Menu>gear>A4>Preset MF distance
After you have finished taking the picture(s), just press whatever button you use for Preset MF and it will return to the focus mode you were in previously. I wish I had figured this out 6 years ago 
