dwileye13 wrote:SNIP
There are no more waters in all of Charis that are better described as coastal waters as Gulf of Dohlar, Hankey Sound, Gulf of Tanshar and the Bay of Bess. This is where they will dominate the seas and control all ocean commerce to a great degree.
The term “coastal waters” is being thrown around rather casually. “Coastal”, as it seems to be used here, implies “narrow and shallow”. Depth of water on nautical charts is shown by color. Safehold standard seems to be the shallower the water, the darker the shading.
We need to add in the concept of “tide” to fully appreciate what “coastal waters” indicate. Tide is the regular rise and fall of ocean waters. The depths shown on nautical charts (sailors refer to maps as charts )are all given at a specific time in the tide cycle, usually either at high tide or low tide. E,g, on a “low tide” chart, the depth shown is the only time the water is actually that deep. At all other times the depth is greater at that spot. For an area with a 15 ft tide, the depth of water shown as a 10 ft spot on the chart will be 25 ft at high tide.
Tide is not current. Configuration of the land creates what are referred to by landsmen as “tidal” currents. Open the map and look at Schwei Bay. Note the narrow entrance (Schweimount Passage), and the 2 very narrow spots south of the entrance. When the tide is rising, the level of the entire bay will be moving to a level 15ft higher. The reverse flow of the ebbing tide will bring the level back to 10 ft at our spot, The "tidal current” is the flow of water into and out of embayments on the coast. As with pipes and hoses, the pressure increases as the amount of the flow increases. The speed of the water flowing in or out (the current)will increase at narrow spots. Schwei Passage is going to be a wild place with the whole Bay passing through there twice every tide cycle. The entrance to the Bay of Bess will experience a lot of “tidal” action as the tide rises and falls.
Steam powered vessels have a huge advantage over sail in coastal waters because they can move against the tidal currents when sail can only do so if the winds are right.
The map shows areas of shallower depths away from land. These are called “shoals” or “banks”. As the tide ebbs (drops) over these areas the waves on the water's surface change which makes shoal areas easy to spot (in daylight) Ship's navigators and captains know where they are, where the shallow areas are (the Archangels left very detailed maps) and the time of the tidal cycle. Ships can operate (very carefully) in shoal waters.
It's premature to assume that water depth increases slowly or quickly as we move away from the land. Generally the near shore bottom will have a shape similar to the land that comes into the water. A flat plain on the shore is likely to have a slowly increasing depth in the water that mariners will treat cautiously. A steep slope to the water will most likely have water depth increasing much faster than the the flat plain area. Unfortunately, we have no idea of the topography is in these areas to give us clues to the shape of the sea bottom. Sailors treat any approach to land as a risky.
The ICN will know of any areas with rapidly shoaling bottom based on the accuracy of the Archangels maps and the fact the merchant fleet will have been sharing notes with other merchants and the Navy on the areas they go through for centuries so any area where there has been significant change from the original maps will be known.
So, if the Charis insist on having the HMS "Marhy Sue" in underwater actions...
(waive all rights, just humor)