Check my math
OK here is a typical Long Island Sound situation.
I want to go due west.
The wind is light coming directly from the west.
The current is strong also coming from the west.
I'm sailing some old shoe with blown out sails that on a good day can tack through 100 degrees.
I'm making a blistering 3 knots through the water.
With no current I could tack tack to my destination doing my 100 degree tacks about 50 degrees off the wind.
With the current I've got to steer about 40 degrees up wind which of course I can't do in this situation.
The end result is that the best I can do is north or south and I'll never go west unless the tide turns. Maybe 5 degrees and 185 degrees but not much more.
Is this what you get?