Countdown to departure

This morning (Friday 7/6/24) I ran the weather routing software based on a departure time of 0900 tomorrow morning (Saturday 8th June). The result shown above, requires some explanation and a lot of qualification.

In theory any boat performs predictably in defined conditions. Performance is a product of the boat's vital statistics - length, depth, sail area, shape, weight etc, etc and the conditions faced at sea - relative wind direction, strength, waves and swell. 

These weather related factors are contained in 'grib' files that can be downloaded over the internet. They are created by complex computer algorithms and of course, different algorithms (models) can give different results. Sometimes these results can be very different and that's what I was finding last week. So when that happens one needs to be cautious - especially if one predicts bad weather and another doesn't. The other thing to bear in mind is that the further into the future the model looks, the less reliable the forecast. Not surprising really.

Now then, in addition to grib files, there are computerised files that predict the performance of one's boat. For many modern boats, these files have been built by professionals who, supposedly know what they're doing. However, for older, little known boats, like the Biscay 36, which is what Bonny is, they aren't available. All is not lost though. One can either use one for a similar boat, or adapt one, or build one, oneself. That's not nearly as clever as it sounds though, one just needs to populate a table with wind speed on one axis and boat speed on the other. Once one has a pretty good feeling for how the boat performs in various conditions (plus guess work for the nasty bits) it's straightforward but it's a big table and so takes ages.

That's why it was only after trying the other options and testing them out on my trusty Raspberry Pi (computer) that I finally decided to build my own. The problem with the other options was that even when based on pretty similar boats, they predicted performance that I knew Bonny would never be capable of, nor I suspected, would the original boat. For example, I don't know of any cruising boat of a similar size that's capable of sailing at 6 knots at an apparent angle of 35° in an apparent 35 knot wind! It just doesn't happen. But if your computer 'thinks' it does, it will give you some very spurious results. That's even before taking account of the weather not being as forecast and the crew being reluctant to sail like professional ocean racers!

So, as I say, I built my own using what I hoped were far more realistic performance indicators and that's what produced the result above, once it and the grib file were run through the weather routing software. 

Returning to the graphic; the thick green line and the blue arrows with feathers studded along its length, are the key features. The line is the recommended route and the blue arrows indicate the direction and strength of the wind the boat is predicted to encounter en route. There's also a clever little gizmo marker (not shown) that one can move along the route with a mouse, to see where on the route, the boat should be at any given time. Of course, one has still got to sail the boat! The computer can't do that, thank goodness!

Frankly, I still don't believe it, but we'll see. I'll run it again in the morning on the latest grib and will post the results below in case you're interested.

The advantage I have now - assuming Starlink co-operates, is that I'll be able to update the grib every day and refresh the recommended route.

Next, after days of dithering, I finally decided to de-frost the fridge. Of course I'd left it too late, but a saucepan of hot water worked wonders!

Then (about 1230) off to the supermarket to stock up for the passage $$$$$! I hope I got enough meat for Vince - he's the opposite of a vegetarian!

Then back to the boat stow the supplies and tackle the Dinghy and outboard. Gary has kindly agreed to act as dinghy chauffeur this evening and in the morning when I will need to check out. 

By tackle the Dinghy, I mean: 

1) Remove the outboard engine and stow it on its bracket on the back of the boat - great fun in a lively chop with the dinghy bouncing all over the place.

2) Haul the very heavy dinghy up on deck using a mast head halyard and the mast winch (essential). More fun.

3) Remove the floor boards and stow them under the forward berth. This was when I realised how pointless my making Vincent's bed was earlier. Everything had to come out including the mattresses! 

4) Wash all the crap off the inside and outside of the dinghy

5) Fold it up and wrap it in its cover.

6) Lash it down on deck

7) Tidy up.

The whole palava took me nearly four hours. Bermuda Customs formal requirement is for you to leave within one hour of checking out! That's why I press ganged Gary to act as chauffeur!

By the time I'd finished, Gary was over for coffee (and courtesy of Melissa's farewell present) oat chocolate chip cookies  - yum, yum, they were delicious!

Then, time to get ashore and bus it to the Airport to meet Vince - now due to land at 7.26! His bed never did get re-made!

Hopefully we'll be able to get food out somewhere in St George's later.

We did - met up with Gary for dinner in the White Horse - thanks Vince.

Tomorrow (Saturday) we are aiming for an early breakfast and then Gary will take me ashore to check out. Oh and I've got to take the cockpit table down before we leave. 

As of Friday evening, fresh south westerlies are forecast for tomorrow which is ideal.

Gary came over for breakfast at 0715 as planned then took me ashore to check out and brought me back.

I checked the weather and fought with the weather routing software and lost while Vince went for a swim (probably the ony one he'll have on the trip). Then we went over to the fuel dock to top up the water tank - I forgot to run the water maker yesterday. Then passed by Tribute to say goodbye to Melissa (Jeff was visiting relatives back in the USA).

We eventually exited the Town Cut st around 1100 rather than the planned 0900.

Well, I said I'd post the updated weather route and here it is ....

No I can hardly believe it either!  Look at that detour. It just goes to show how quicky the weather can change. There's no Report with this one because it predicts we'll take longer than the 8 day grib and so the software can't complete the route. Anyway, given it changed so much over night it's just as likely to change again, so we're not dashing off in a north easterly direction as suggested, but heading more or less directly north for Lunnenberg.