Tide & current

[KPII]

Hi All,

I just started playing SHIV a couple of weeks ago (but probably have a 100 hours in the log by now) and just wanted to let you know that the guides and training materials posted here has been invaluable. I have been on a very steep learning curve since this is the first sub simulation I play since 1986.

In the first real career game I started out with manual targeting, but after many hours of play with a very low hit percentage (I use FTT 2.5), I decided to go back to automated targeting, as I seem to have enough of a challenge with approach, positioning and especially getting away after a launch. Once my tactical skills are improved I'll of course go to manual targeting, but for now I have my hands full (and I'll need a higher spec puter, so the cursor lag doesn't cost me valuable seconds).

My question is regarding the impact of tide and current on torpedos and submarine, but since it's already posted at the UBI forum I'll just link to it and hope someone can respond: http://forums.ubi.com/eve/forums/a/tpc/f/6421019045/m/4001043065

I'm curious because it looks like the boat speed displayed is the actual speed over ground - I would have expected an effect from tide/current since the game is supposed to be a simulation and these factors are crucial for sub tactics (I assume, since I only know about navigation on the surface).

Many thanks!

[castorp345]

in game there do appear to be tide/current effects when surfaced... try this: center your rudder and check your heading, then try running for an hour or so without your helmsman following a nav plot, then check your heading again. :smug:

the heading deviation you'll observe might be weather related though... 'have to do some more experimentation to determine. also, these effects do not hamper your boat's course keeping ability when submerged. as well, your helmsman will always automatically compensate for "tidal/current drift" when following a nav plot, so this really only comes into play if you're using self-imposed manual navigation rules (like me! :know:)

cheers
hc

[KPII]

Thanks for the response! I have noticed that some corrections are made by the helm i.e. when lying "at drift" there will be minor rudder corrections, but since the map doesn't display currents and tidal flows it's impossible to acertain if they are correct adjustments or just "dummy corrections".

Having some information on current/tide on the map, would really make for some interesting tactical situations. For example, between ALDERNAY (northern most of the British Channel Isles) and the French Coast you have a tidal current of up to 9 knts ("The Aldernay Race") - imagine using such a current as your exit strategy ... on the surface the sub could be doing 30 knts. ... no more creeping out with 1 knts. - of course you would have to make sure the DD's are facing the current :)

The lack of data provided really annoys me ... for example, when doing 90 degree rudder it looks like boat speed is the same as with rudder amidships - I always use less rudder to ensure that I make some way across ground on low speed, but I'm uncertain if it has any effect.

[-Pv-]

I have seen no evidence there is tide or currents in the game. On the surface wind seems to influence the boat. This is easily seen in reduced headway in storms. The helmsman/planesman animation is for looks.

There are many infamous areas in the pacific with strong currents reducing speed to 1 knot at ahead full. If these were being simulated I'm sure we'd be hearing a lot from the "outagas" crowd.

If you watch the rudder text in the navigation/control bar, you can see any adjustements being made to the rudder by the navigation system. Typically on a long stretch between waypoints, I see no compensations being made until very close to the next waypoint which is typical as the resolution to maintain the heading gets smaller and smaller.
Just as waves are suppressed in dock to ease the tasking of pulling up near the pier and avoiding traffic, I think wind effects are suppressed also.
-Pv-

[castorp345]

i can only reiterate:

center your rudder and check your heading, then try running for an hour or so without your helmsman following a nav plot, then check your heading again...

now perhaps this is indeed just an effect of wind pushing the head of the boat around and so not an actual modelling of currents or tides (I honestly haven't taken the time to explore this), but something is causing, depending on location and sea-state, fairly significant heading drift when not using the navigation plot...

:ping:

[Berengal]

I see periodic compensation all the way between waypoints, but had until now thought it was only compensating for low heading resolution. I've also noticed that speed varies, but this could just be wind. What has happened to me, however, is destroying my ship on sandbanks that aren't on the map. It could just be they're really small and I've been missing them, but this happens in areas I've sailed through several times, and it could be tides. I think I'm going to hang around some shallow waters and prod the depth for a couple of days now to do some testing.

[-Pv-]

"...What has happened to me, however, is destroying my ship on sandbanks that aren't on the map..."

I'm absolultely certain any water shallow enough to bottom the boat IS visible on the map and not due to sandbars being moved around by tides and currents.
I strongly suggest you use the waypoint plot tool while zoomed in tight on the map (TAB key or click the magifying glass on the map.) The autopilot will keep you out of harm while you are zooming at high time compression. Think of it as giving your navigation officer a plot and counting on him to give the helm all the correct turns at the right time while you concentrate on strategy and managing your crew.

Zoom in to your waypoints to make sure small bits of land you cannot see when zoomed all the way out are not too near your plots. The brighter the background color, the shallower the water. Right click on the magnifyier to zoom back out.

land] color1) color2) color3) color4) color5-deepest blue

Land
White color1 = 0-48 feet
color2 = 48-175
color3 = 175-490
color4 - 490-850
color5 = 850+
-Pv-

[KPII]

Thanks a lot for the responses - I have done a few more tests and it does look like the helm is correcting for wind (CTRL-W gives a weather report in TM v1.0), but the corrections are not consistent, as they will sometimes be with the wind when not following a plotted course.

I have seen no evidence there is tide or currents in the game. On the surface wind seems to influence the boat. This is easily seen in reduced headway in storms. The helmsman/planesman animation is for looks.

There are many infamous areas in the pacific with strong currents reducing speed to 1 knot at ahead full. If these were being simulated I'm sure we'd be hearing a lot from the "outagas" crowd.

It would be an excellent feature to have in - perhaps as a realism option so the "outagas" crowd can opt out. Tidal navigation is a tricky business on the surface, so I would expect it to be even more complicated when submerged. This would of course require a map with the tidal streams, detailed depth information and some basic almanac information, but that could be made very basic so it doesn't get too complicated. For example, just include arrows on the map with some major tidal streams and an average value, a basic table with tidal heights for each major location (example below) and then a small conversion formula for the skipper to calculate the speed and direction of the tide as well as the speed of the major tidal streams.

Manila:
0600: 8 meters
1200: 2 meters
1800: 10 meters
2359: 4 meters