That's similar to what I have, but I think I've maybe got something wrong along the line. I'd been following the tutorial, the St Barts one which is an Island I know, but that might be where I've gone too far.
I set the server to use VE and zoomed in. Set the QMID to level 11 in the first instance and then drew several exclude polys over the docks (Blue arrow). (In hind sight I probably didn't need these as I'll be using a photo tile in this area) - I assume the exclude in your image above is for shorelines?
Next I changed to QMID level 15 and drew a hydro poly fully covering all of the QMID tiles that would be intersected by my exclude polys (Red arrow)
Then I drew several polys and set them as "holes" though the water poly. (Black arrow) I was having real difficulty zooming in an out while drawing the polys (other than the Hydro poly as it covers such a large area) so I used several smaller polys and overlapped them, is this wrong?
Well, yes. Holes are used to create islands in an hydropoly. In your case, there are no islands, only water on one side and land on tother (with an extra few lakes).
You need only one exclusion poly which intersects part of the default coasline contained within a particular QMid11 rectangle. This will exclude all coastlines within that QMid11 rectangle.
If you look at my screenshots, the red triangle is the exclude (all waterpolys) exclusion. The blue polygons are the hydro-polys and the green polygon is the flatten for the shipyard.
Sorry George, one more question from now. Does the Flatten have to be a single poly or can I use smaller overlapping ones, due to the problem I'm having with zooming in while drawing it.
The easiest way is to draw a triangle anywhere and set the properties to "Airport background flatten".
Now, zoom in and with the polygon tool selected, hold down the "i" key and click on the polygon. This will insert a new vertex into the polygon. Watch out for the tooltip and click only when it shows "Polygon of type ...".
Now, select that point (when the tool tip sats "Point #"), hold down the left button and drag to the required position.
Watch out that you don't drag the complete polygon. If you do, use the "Undo" button and try again.
You can refine it further if you zoom in again and insert further points.