So That’s a Bora!

Tuesday, May 24, 2019

A Bora is a strong cold, wind in the Adriatic, coming off of the mountains and typically only experienced in winter.   Welcome to winter.

Last night while sitting at anchor and enjoying a bit of kayaking, I noted that the winds were getting strong and the waves, in a bay, were getting unusually choppy.   I consulted the weather maps and decided to head back to a marina for the night.

Unfortunately, I didn’t start my journey until after 7pm and by the time I reached the appointed marina, it was dark and the winds in the area were topping out at 40+ knots.   Given that I am single handing, I opted to stay in the bay nearby and drop an anchor.   Where I was originally would likely have had significantly higher waves as the wind had 8 or 10 nm to run over the water, but here, near the marina, the wind only has a few hundred feet.   Choppy, with short sharp waves, but not too bad.

Even though I arrived around 10:00pm the last of the light was gone and around 11pm I decided it was too dangerous to try to med moor alone in such strong winds and dropped anchor.  The winds have been howling constantly ever since.  It is now 16 hours since the winds started, with another 6-8 hours to go if I am to believe the weather maps.   Here is what it looks like right now.  Red is bad.   Black is really bad.  I am essentially sitting where that green dot is (Split).

So that’s a Bora.   This is a cold, intense wind, and while the wind maps show about 15-20 knots, the gusts get up into the mid-40 knots (about 70kph).   Apparently up towards Sibenik, a 200+ kph gust was recorded earlier in this decade.   I had read about them in the cruising guide, and noted the caution, but they typically only occur in winter, so not too much to worry about.  It’s almost June right?

Well, the weather here has been unusually cold, I hear it is the same in Toronto, and this is a result for at least this little corner of the world.

One of the other benefits of moving the boat was that at my prior location, this wind would have been pushing me toward land if the anchor gave way, and I would have had very little time to respond.   In this location (although I was hoping to be tied to a dock), if anything goes wrong with the ground tackle (anchor and chain), the boat will be pushed deeper into the bay and I would have plenty of time to respond before being in any serious difficulty.

The good news is that the anchor has held well, and I will sit here until early evening and decide whether to try docking in the winds (whatever their state at 6 or 7pm) or just stay here for the night again.   I know my anchor is holding and the winds should diminish.

Now I know what a Bora is, I understand the intensity!

I thought I would post a picture of my boat’s movement while at anchor during that bora.   I finally found a decent anchor alarm app on iTunes (Anchor Alarm).  (The phone has to remain on the boat, so it won’t work when I leave the boat).

Update:

Here is a photo of the boat’s location through the night (11pm – 3pm; about 16 hours in total):

I had a bit over 200′ of chain out in 33′ of water. Note the spots when the boat was pushed waaaay back. Those would have been strong gusts.  With a 49.5kg (about 110 lb) anchor and 200′ of high test chain out (at about 1.5 lbs/foot) that is about 400 lbs of ground tackle out.