diff --git a/include/file.h b/include/file.h
index 173293d5..22fcf0c8 100644
--- a/include/file.h
+++ b/include/file.h
@@ -145,6 +145,7 @@ enum {
     EF_PACKING,
     EF_RESOURCES,
     EF_NATION_STATUS,
+    EF_SECTOR_NAVIGATION,
     /* Views */
     EF_COUNTRY,
     /* Number of types: */
diff --git a/include/nsc.h b/include/nsc.h
index 850fd6a7..2c3f7c2b 100644
--- a/include/nsc.h
+++ b/include/nsc.h
@@ -237,6 +237,7 @@ extern struct symbol agreement_statuses[];
 extern struct symbol plague_stages[];
 extern struct symbol packing[];
 extern struct symbol resources[];
+extern struct symbol sector_navigation[];
 
 /* src/lib/subs/nstr.c */
 extern int nstr_comp(struct nscstr *np, int len, int type, char *str);
diff --git a/include/sect.h b/include/sect.h
index 5cbaf28f..e1f0134d 100644
--- a/include/sect.h
+++ b/include/sect.h
@@ -108,6 +108,7 @@ struct dchrstr {
 };
 
 /* for d_nav */
+#define	NAV_NONE    0		/* ships can't navigate */
 #define	NAVOK	1		/* ships can always navigate */
 #define	NAV_02	2		/* requires 2% effic to navigate */
 #define	NAV_60	3		/* requires 60% effic to navigate */
diff --git a/src/lib/global/file.c b/src/lib/global/file.c
index f5fd4e25..d4816130 100644
--- a/src/lib/global/file.c
+++ b/src/lib/global/file.c
@@ -189,6 +189,8 @@ struct empfile empfile[] = {
     {EF_RESOURCES, "resources", NULL, symbol_ca, PTR_CACHE(resources, EFF_CFG)},
     {EF_NATION_STATUS, "nation-status", NULL, symbol_ca,
      PTR_CACHE(nation_status, EFF_CFG)},
+    {EF_SECTOR_NAVIGATION, "sector-navigation", NULL, symbol_ca,
+     PTR_CACHE(sector_navigation, EFF_CFG)},
 
     /* Views */
     {EF_COUNTRY, "country", NULL, cou_ca, UNMAPPED_CACHE(struct natstr, 0)},
diff --git a/src/lib/global/nsc.c b/src/lib/global/nsc.c
index 7f8adbb9..3557c67a 100644
--- a/src/lib/global/nsc.c
+++ b/src/lib/global/nsc.c
@@ -167,7 +167,8 @@ struct castr dchr_ca[] = {
     {NSC_INT, NSC_CONST, 0, offsetof(struct dchrstr, d_mnem), "mnem", EF_BAD},
     {NSC_INT, 0, 0, offsetof(struct dchrstr, d_prd), "prd", EF_PRODUCT},
     {NSC_INT, 0, 0, offsetof(struct dchrstr, d_mcst), "mcst", EF_BAD},
-    {NSC_INT, 0, 0, offsetof(struct dchrstr, d_nav), "nav", EF_BAD /* FIXME */},
+    {NSC_INT, 0, 0, offsetof(struct dchrstr, d_nav), "nav",
+     EF_SECTOR_NAVIGATION},
     {NSC_SITYPE(i_packing), 0, 0, offsetof(struct dchrstr, d_pkg), "pkg",
      EF_PACKING},
     {NSC_FLOAT, 0, 0, offsetof(struct dchrstr, d_ostr), "ostr", EF_BAD},
@@ -781,3 +782,11 @@ struct symbol resources[] = {
     {offsetof(struct sctstr, sct_uran), "uran"},
     {0, NULL}
 };
+
+struct symbol sector_navigation[] = { /* for d_nav */
+    {NAV_NONE, "land"},
+    {NAVOK, "sea"},
+    {NAV_02, "harbor"},
+    {NAV_60, "bridge"},
+    {0, NULL}
+};