Random Ocean and Island Terrain Tables

Earlier today there was a request on G+ for ocean and water terrain tables.  I don't know of any and the lack of them dates back to the 1e DMG, which stated that the DM must draw them in by hand.  Chivalry & Sorcery has a similar statement.  

I think the biggest reason no one published them is that you can't reliably randomly generate a meaningful coast line, there's no guarantee in these tables that your coast won't encircle your map or have a strange gap in it.  I've tried to control for that by assuming that you map the coast while you sail along it, but your result WILL vary.

If you have any suggestion for improvement leave a note, drop me a line or put a message in a bottle and heave it overboard.  Of course, I'm up near the falls of the Mississippi, so the last probably won't reach me.

Ocean Terrain Generator

Roll	Deep Water	Shallow Water	Island	Big Island	Coast Trends
1	Deep Water	Shallow Water	Reef	5 Hex	Continues in same direction
2	Deep Water	Deep Water	1 Hex	5 Hex	1 hex face left
3	Deep Water	Shallow Water	1 Hex	5 Hex	1 hex face left
4	Deep Water	Shallow Water	1 Hex	6 Hex	2 hex faces left
5	Shallow Water	Deep Water	2 Hex	5 Hex	Continues in same direction
6	Deep Water	Shallow Water	1 Hex	5 Hex	1 hex face right
7	Deep Water	Shallow Water	1 Hex	5 Hex	1 hex face right
8	Deep Water	Shallow Water	1 Hex	5 Hex	2 hex faces right
9	Deep Water	Reef	2 Hex	6 Hex	Continues in same direction
10	Shallow Water	Shallow Water	1 Hex	6 Hex	Continues in same direction
11	Deep Water	Shallow Water	1 Hex	6 Hex	1 hex face left
12	Deep Water	Reef	1 Hex	7 Hex	1 hex face left
13	Deep Water	Shallow Water	2 Hex	8 Hex	2 hex faces left
14	Deep Water	Shallow Water	1 Hex	7 Hex	Continues in same direction
15	Reef	Island	1 Hex	8 Hex	1 hex face right
16	Deep Water	Shallow Water	3 Hex	9 Hex	1 hex face right
17	Deep Water	Shallow Water	1 Hex	10 Hex	2 hex faces left
18	Deep Water	Shallow Water	3 Hex	11 Hex	Inlet or fjord, coast line comes back out the same face it entered. Roll 1d6-2 (min 1) to determine depth of fjord in hexes.
19	Deep Water	Island	4 Hex	12 Hex	Continues in same direction
20	Island	Shallow Water	Big Island	Coast	Continues in same direction

Deep Water vs Shallow Water - There's no set depth dividing the two, shallow water effects (shortening wavelength as determined by the distance between the wave crests and heightening of the crests) occurs when the depth of the water < 1/2 the the wavelength .
For practical purposes, deep water can be considered anywhere where you can't sound the bottom due to the depth.  Sounding the bottom is done with a 150 foot lead line, marked off in 6 foot fathoms.

Reef - a rock or formation lying below mean low water, but protruding up from the surrounding sea floor.

Island - approximate size in hexes or squares if that's what you're mapping on.

Coast - The first time you encounter a coast it will be perpendicular to the direction you are sailing.  Use this column when as you sail along it to determine how the direction of the coast changes in reference to the direction of travel.