Jeremy built FastSeas for a couple of reasons, but primarily it was to create a tool he knew we would need when we set off cruising again. And use it we have. Most recently, the departure planning feature helped us hone in on a decent weather window to take Mischief and Calypso north from Deltaville to Oak Harbor.

Departure planning is, pretty simply, a tool that helps you see what might be a good weather window to get to your destination. It’s not just about good weather for leaving but about the trip as a whole. If you’re going on a four hour jaunt across the harbor, this might not make a lot of difference; if you’re trying to run 100 miles north with a boat that’s got a suspect rig and engine (cough), well, you might want to do your best to keep wind and waves light.

Not that you can 100% predict the weather, mind you.

To use the departure planning feature on FastSeas, first you want to make sure you’ve set a polar. A polar is a set of data that indicate vessel performance; you can find the numbers for a lot of production boats. Don’t have one? Have the system generate a simple polar for you which you can tweak.

On this last trip, since we were not planning to sail at all, we set the criteria as if we were a power boat.

Next up is to choose a route. Select a start point and an end point, then go to the route page (the teardrop icon) to set the date you’d like to start looking for a window. If you don’t do this step, the route will calculate (and so will the departure plan) from right that minute. So maybe you know you’ll be ready to go in a week. Start looking for a window early but set the departure day from that week out date.

When we did this recently, we started looking about a week before we thought we might be ready to leave the boatyard. We ran the departure plan a few times a day, watching the weather shift as time got closer. Doing this numerous times allowed us to see what a regular pattern of fronts looked like as well as what kind of time we' might have after a front to get north. Doing this numerous times meant we were hyper aware of weather changes as the forecast changed. And doing this numerous times allowed us to choose just the right time to head north.

Departure planning is a super useful tool for passage making. Was the passage we just did a long arduous one? No. But the unknowns around Mischief’s rig and engine made us want to be cautious and conservative. If we’d been sailing on Calypso, we’d have been looking for a different kind of weather window entirely!

Which brings up another point too - that old “it depends” thing. One person’s perfect weather window is another person’s boring-motorboat-ride-why-go-on-a-sailboat-anyway window. You have to decide and know for yourself what works for you.