Well, it seems my Frankenstein version is going to be built on Beta 1 Patch 7, as i had got that to a nice balanced state in terms of XP gains and Item values (stats etc), and various other things (like the 'Mach 3' seagull problem, getting storms at sea in direct sail (iirc), good sea/weather effects in general etc), BUT that is so far behind in terms of the new (better) world map and the impressively polished GUI we have in Beta 3.1 onwards. So......yeah.
Put it this way, having worked so closely on this Pieter, if you suddenly had to go back to Beta 1, and try to import the best/least bugged bits since then over to that, would you feel enthused about that!
Anyway the other option is to build from Beta 3.1 and 'retro-fit' any changes that break the better bits of Beta 1. Either way it is probably going to be a long painful and maybe simply not possible journey. I won't know until i start comparing files side by side in winmerge!
Not entirely sure I follow you there. If you use WorldMap, then Open Sea Mod OFF is quite fine, isn't it?
Also the [0]-key to disable the DirectSail updates might help to prevent the CTD.
If it then DOES still occur, then the problem isn't actually related to DirectSail but has to be searched somewhere else.
I run a game that allows me to go in and out of Direct Sail mode, so when i need to be quick i can use the World map (map navigation mode), even though much of the time i will spend in realtime (or time x3, any more and it looks too weird!) sailing directly from port to port. Beta 3.4 and Beta 4 always CTD for me in direct sail mode, which might be related to my XP OS, as that has shown issues, so could be related to memory loading issues (as with the missing ship icons in the shipyard menu, or probably the reason behind the messed up looking sea in Beta 4 (Beta 3.4 is still ok currently)).
I selected the Open Sea Mod as ON (1) in InternalSettings.h, but leave most of the 'Ironman' settings off so i can move freely between worldmap and direct sail mode (helps with playtesting).
The issue with this approach is the current disconnect between these two modes, so being close to land in the worldmap will not mean you are when you transition to direct sail, you seem, as Hylie mentions, to be placed at sea with the land on the horizon when using the Open Sea mod. So this particular configuration does not work smoothly anymore (it does in Beta 1 Patch 7, but that was using the older Islandcell hopping system, but the transitions are smooth, from worldmap navigation to direct sail mode; if close to land in one mode you are in the other).
But as i'm supposed to be in Ironman mode for the Open Sea mod, i would normally only be able to direct sail anywhere, so would not notice this particular issue. Anyway it is something i will look at in the Open Sea mod and see if it has to be that way or maybe i can make it work alongside the worldmap navigation mode?
Anyway the problem for me in terms of testing Beta 4 (or 3.4) is that with the Open Sea mod working like this, the chances i will CTD, even if sailing most of my journey in the worldmap navigation mode, is very high as the time it takes to sail in realtime to an island on the horizon is (so far) always enough time for the CTD in direct sail mode.