diff --git a/samples/ships.bas b/samples/ships.bas
index 381c68b..3976962 100644
--- a/samples/ships.bas
+++ b/samples/ships.bas
@@ -8,14 +8,12 @@
 
 120 hcolor=3
 130 x=140:sd=0:s=sh
-140 di=0:mm=3:dim dx(mm),dy(mm),ds(mm),ox(mm),oy(mm),os(mm)
+140 di=1:mm=5:dim dx(mm),dy(mm),ds(mm),ox(mm),oy(mm),os(mm)
 150 for i=1 to mm:dx(i)=0:dy(i)=0:ds(i)=0:next i
 
 200 xdraw s at x,10:ox=x:os=s
-210 for i=1 to mm
-220 ox(i)=dx(i):oy(i)=dy(i):os(i)=ds(i)
-230 if dx(i) then xdraw ds(i) at dx(i),dy(i)
-240 next i
+210 ox(di)=dx(di):oy(di)=dy(di):os(di)=ds(di)
+220 if dx(di) then xdraw ds(di) at dx(di),dy(di)
 
 300 ky=peek(-16384):if ky < 128 then 400
 310 poke -16368,0
@@ -29,16 +27,14 @@
 410 if x < 10 then x=10
 420 if x > 270 then x=270
 
-500 di=di+1:if di > mm then di = 1
-510 if not dx(di) then 600
-520 ds(di)=ds(di)+1:if ds(di) > dc+3 then ds(di)=dc
-530 dy(di)=dy(di)+2:if dy(di) > 160 then dx(di)=0:dy(di)=0:ds(di)=0
+500 if not dx(di) then 590
+510 ds(di)=ds(di)+1:if ds(di) > dc+3 then ds(di)=dc
+520 dy(di)=dy(di)+3:if dy(di) > 160 then dx(di)=0:dy(di)=0:ds(di)=0
+590 di=di+1:if di > mm then di = 1
 
-600 xdraw os at ox,10
-610 for i=1 to mm
-620 if ox(i) then xdraw os(i) at ox(i),oy(i)
-630 next i
-640 goto 200 
+600 if ox(di) then xdraw os(di) at ox(di),oy(di)
+610 xdraw os at ox,10
+620 goto 200 
 
 49999 end
 50000 $shape src="ships.st", poke=yes, init=yes, assign=(sb="sub-left", sh="ship-left", dc="depthcharge-1")