[MP2]

pawn Код:

stock IsPlayerInWater(playerid)
{
    new lib[16], anim[32];
    GetAnimationName(GetPlayerAnimationIndex(playerid), lib, sizeof(lib), anim, sizeof(anim));
    if(!strcmp(lib, "SWIM", true) && !isnull(lib)) return 1;
    return 0;
}

Surprisingly simple. Get isnull in y_utils (part of YSI): https://sampforum.blast.hk/showthread.php?pid=1696956#pid1696956