Universal Diesel 5424 Big Oil Leak

[svalibi]

I am currently in the Bahamas. I was preparing to move to a different anchorage today when I discovered I have a pretty big problem. When checking the oil, the level seemed a little low, and I noticed a small amount in the tray below the engine. I added some and got my wife to crank up so I could watch for leaks. The second she cranked, oil started pouring out the block near the starboard aft motor mount. We shut it down quickly and started to investigate.

Here is the leak:



I found this below the leak, and it seems like it was in the hole:



Any ideas what this is or any solutions? I've looked through the manual without much luck so far. Any help is much appreciated!

[FPNC]

There is more than one dipstick hole in the block of most Kubota engines. If a dipstick hole is not used, it is plugged. The hole is about 3/8" in diameter. If the plug has fallen out, you can reinstall it with a bit of silicone or buy a new plug.