@Serge1966
Hi Capt’n
This is a know problem with apparently no real solution
https://community.windy.com/topic/9680/route-planner-going-crazy-between-hawaii-and-marshall-islands/10?_=1752571331269
The only way I can see to use the route planner when crossing the antimeridian is to split the route into two parts: one up to the antimeridian and another from that longitude, with a departure time close to the arrival time of the first leg. For example, to 179°E and from 179°W at the correct latitude to maintain a great circle path for the total passage.
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I don’t know what is the average speed of your ship, but from the Asian side of the Pacific to the antimeridian you probably need a week which is already a long time frame for a reliable weather forecast.