diff --git a/include/land.h b/include/land.h
index 65520a9f..6d2fc0e4 100644
--- a/include/land.h
+++ b/include/land.h
@@ -42,7 +42,7 @@
 #include "nsc.h"
 #include "retreat.h"
 
-#define N_MAXLAND	30
+#define LND_TYPE_MAX	30
 #define LAND_MINEFF	10
 #define LAND_MINFIREEFF 40	/* arty must be this effic to fire */
 
@@ -178,7 +178,7 @@ struct lchrstr {
 #define putland(n, p) ef_write(EF_LAND, (n), (p))
 #define getlandp(n) (struct lndstr *)ef_ptr(EF_LAND, (n))
 
-extern struct lchrstr lchr[N_MAXLAND + 1];
+extern struct lchrstr lchr[LND_TYPE_MAX + 2];
 
 struct llist {
     struct emp_qelem queue;	/* list of units */
diff --git a/include/plane.h b/include/plane.h
index b501659d..a0bb2f96 100644
--- a/include/plane.h
+++ b/include/plane.h
@@ -39,7 +39,7 @@
 #include "queue.h"
 #include "sect.h"
 
-#define N_MAXPLANE	40
+#define PLN_TYPE_MAX	46
 #define	PLANE_MINEFF	10
 
 struct plnstr {
@@ -138,7 +138,7 @@ struct plist {
 #define putplane(n, p) ef_write(EF_PLANE, (n), (p))
 #define getplanep(n) (struct plnstr *)ef_ptr(EF_PLANE, (n))
 
-extern struct plchrstr plchr[N_MAXPLANE + 1];
+extern struct plchrstr plchr[PLN_TYPE_MAX + 2];
 
 struct shiplist {
     short uid;
diff --git a/include/ship.h b/include/ship.h
index e3fd700c..16f8220e 100644
--- a/include/ship.h
+++ b/include/ship.h
@@ -42,7 +42,7 @@
 #include "misc.h"
 #include "retreat.h"
 
-#define N_MAXSHIPS	40
+#define SHP_TYPE_MAX	46
 #define	SHIP_MINEFF	20
 
 /* bit masks for the autonav mode flags */
@@ -183,7 +183,7 @@ struct mchrstr {
 #define putship(n, p) ef_write(EF_SHIP, (n), (p))
 #define getshipp(n) (struct shpstr *)ef_ptr(EF_SHIP, (n))
 
-extern struct mchrstr mchr[N_MAXSHIPS + 1];
+extern struct mchrstr mchr[SHP_TYPE_MAX + 2];
 
 struct mlist {
     struct emp_qelem queue;	/* list of ships */
diff --git a/src/lib/global/land.c b/src/lib/global/land.c
index b2f7a7f3..9bd04bae 100644
--- a/src/lib/global/land.c
+++ b/src/lib/global/land.c
@@ -41,5 +41,6 @@
 /*
  * Table of land unit types
  * Initialized on startup from land.config and deity custom config (if any).
+ * Terminated by a sentinel with null l_name.
  */
-struct lchrstr lchr[N_MAXLAND + 1];
+struct lchrstr lchr[LND_TYPE_MAX + 2];
diff --git a/src/lib/global/plane.c b/src/lib/global/plane.c
index 5dd72307..4c1c2964 100644
--- a/src/lib/global/plane.c
+++ b/src/lib/global/plane.c
@@ -43,5 +43,6 @@
 /*
  * Table of plane types
  * Initialized on startup from plane.config and deity custom config (if any).
+ * Terminated by a sentinel with null pl_name.
  */
-struct plchrstr plchr[N_MAXPLANE + 1];
+struct plchrstr plchr[PLN_TYPE_MAX + 2];
diff --git a/src/lib/global/ship.c b/src/lib/global/ship.c
index 79b06465..436e4ed4 100644
--- a/src/lib/global/ship.c
+++ b/src/lib/global/ship.c
@@ -43,5 +43,6 @@
 /*
  * Table of ship types
  * Initialized on startup from ship.config and deity custom config (if any).
+ * Terminated by a sentinel with null m_name.
  */
-struct mchrstr mchr[N_MAXSHIPS + 1];
+struct mchrstr mchr[SHP_TYPE_MAX + 2];