extern int shp_may_nav(struct shpstr *, struct shpstr *, char *);
extern void shp_sel(struct nstr_item *, struct emp_qelem *);
extern struct ulist *shp_insque(struct shpstr *, struct emp_qelem *);
-extern void shp_nav(struct emp_qelem *, natid);
+extern void shp_nav_stay_behind(struct emp_qelem *, natid);
extern int shp_sweep(struct emp_qelem *, int, int, natid);
extern enum shp_stuck shp_check_nav(struct shpstr *, struct sctstr *);
extern int sect_has_dock(struct sctstr *);