static inline Owner GetCanalOwner(TileIndex t)
{
	assert(GetWaterClass(t) == WATER_CLASS_CANAL);

	if (IsCanal(t)) return GetTileOwner(t);

	Owner owner_canal = GetTileOwner(t);
	SB(owner_canal, 0, 2, GB(_me[t].m6, 0, 2));
	SB(owner_canal, 6, 2, GB(_me[t].m6, 6, 2));
	/* Canals don't need OWNER_TOWN, and remapping OWNER_NONE
	 * to OWNER_TOWN makes it use one bit less. */
	return owner_canal == OWNER_TOWN ? OWNER_NONE : owner_canal;
}