Originally Posted by glenndamato
Jon: The issue that day was big swells knocking me backwards. The Serenity was full-keel of course but I could not sail close to the wind at all because both the wind and the swells were perpendicular to the coast. If you've tried to close-haul a Downeaster at sea directly against large, steep swells, you know what I'm talking about: the swells rob the boat of forward momentum and actually push you backwards across the bottom. I don't know exactly how far off I was, but I estimate my bow was fully 70-degrees off the wind and I could not make any progress away from the coast. If I came up, I lost rudder control. If I fell off, the wind pushed me toward the coast faster. Maybe someone with a lot of sail trim know-how could have (alone!) configured that boat to claw off, but I couldn't see how to do it. I needed to get the engine back.
I totally can see how that would work.
There is a rule of thumb to calculate how much a current will push you from your heading so can do the math in your head you don't have to chart it.
You take your speed and figure out how many minutes it takes to go one mile.
At three knots for example your go one mile in 20 minutes. You multiply that number times the current and that is how many degrees you will loose.
So if the current is 2 knots and your speed is 3 knots instead of being able to sail 45 degrees to the wind you will be lucky to get 85% off the wind.
But then if the wind is high you have to reef and a reefed sail is not as efficient so you might only be able to manage a beam reach at best and not be able to make progress upwind at all.
Now in the lee shore situation above there is no actual current but depending on the geometry of the bottom it makes sense that there would be effectively an onshore current caused by the wind and waves.
A reefed boat does not point very well, a full keel boat does not point that well. You can't get any speed crashing into waves. Every time you try to point up you hit a wave and the the boat stops.
So yes I totally can visualize the situation.