...AND I see a mistake I own in post#46. "in direction as a vector to any wind it will affect apparent wind differently on each tack as can be easily shown" is wrong,wrong,wrong.Maybe I can complete it as I meant it: "per waves affecting boat speed...sailing in troughs on the soggy tack,pointing into chop on the hard-tack".That relies on the current being the cause of the "vectored" waves,so it's merely a possibility.
likewise Imyself have no clue what this meant(but I wrote it!) " if current can change tack to tack.I say,yes it can,IF the current is NOT "in line" with whatever wind is blowing."As written still wrong.
Anyways,after re-reading all posts,and assuming the duration of a tack is longer than 0 time,0 distance.and that a 25'boat exhibits some "weather helm"..OP asks I `ve felt more weather
helm that on starboard (same wind, same sail trim). I´ve checked the mast
set up with some locals and it seems ok, (rake, shroud
tension). I sail on the Parana river in Argentina
which has a 2.5 knot
current!. Could have been the current the responsible for that?
Since an argument devolved to "can current effect weather helm?"as it often does in a forum...
1)When:true wind,current,and waves are in line (or 180 degrees),sail trim and boatspeed will be the same and helm will not vary.
If wind has effect on weather helm,Current must too.Current versus wind is the same as "more wind"Current affects weather helm.
BUT,Tacking has no effect on weather helm tack to tack.
2)When:true wind steady and current varies in speed but is still "inline" as to direction.Any Resulting wave chop only due to current+wind is also assumed in-line..but varying somewhat.
Current speed increases/decreases against the wind.Sailtrim was not changed,boat heels more and more weather helm momentarily while the navigator puzzles the new condition.A gust of wind is the same thing.Navigator elects to keep the WeatherHelm the same.
So,current hasn't affected his weather helm ...as long as he's able to point higher and maintain the Apparent wind as exactly the same.Maybe to the point where the sails
are useless and the chop stops him.
But,if "sail trim" means keeping sails
"full " as they were before,
boat heels more,goes faster, brings the apparent therefore incident angle closer to where it was per sail trim but stronger.So, Weather helm has been increased by the current.It's the only change.It's the same as having a plain gust of wind which affects weather helm .
But,changing Current does not affect Weather helm tack-to-tack
the boat happens to progress to a place where it "seems to"on a particular tack.It's a possibility
.IE: clearing a Breakwater,rounding a point,thereby entering a new current regime..
When:True wind is steady,current is steady but has a different vector to True wind.
Weather Helm won't change tack to tack.....Unless
a wave train of current+wind is included...Wave direction is commonly different from the wind without current being anyway involved but as a possibility
,in a river or channel,current's contribution,eg:One tack more in the troughs,on the other more pitching,is pretty strong.This is similar to a plain ol crosswind,also possible
.This will make each tack "different"....and the case is like 2) above..I think this means Yes,a change in Weather Helm tack to tack is possible
due to current....