Underwater Rules - DS (long)

G'day,

Here's the DS version...

Beth

> [quoted text omitted]

DIRTSIDE SUGGESTIONS With regard to smaller scale encounters, (thinking here
of vessel scale
more than numbers involved), DS/SG are the more sensible option. The
following is some suggested ideas (modifications) for underwater duels.

Detection Range: Electronic sensors will continue to have long ranges only if
they are acoustic, every other form of radiant energy is absorbed very quickly
by water. However to expedite measures, assume sensor suites in marine vessels
(including amphibious vehicles) have at least some sonar capabilities. For
ease of play the following sensor ranges (based on Fire control rating) are
proposed Superior = 60" Enhanced = 40" Basic = 20" None = 4" if in clear
water, 1" if in turbid water.

Anything outside of the detection range is considered hidden (often just being
in the water is enough to make you hidden, so the usual rules of needing to be
in cover need not apply if just at distance from each other, but it'd help),
however as soon as its detected by one unit then all units on that side know
its position. As in land warfare it isn't possible to go back to completely
hidden once found (pesky AIs...), but it is possible to make it harder to be
hit by going to silent running (i.e. being
semi-hidden). To go quiet you must move less than half of you BMF, do
not use any kind of weaponry or sensors and then pass a reaction test based on
the following: CIRCUMSTANCES THREAT LEVEL
Boat, amphibious walker in shallow      +2
Boat, amphibious walker in deep         +1
All else except non-amphibious          +2
walkers or wheeled vehicles* *Non amphibious walkers and wheeled vehicles stay
found once they've been picked up once.

Until successfully detected again, or until you expose yourself through the
use of active sensors or fire you get an additional D6 target dice, this is in
addition to any you may have already got for soft cover etc.

Weapons: These changes may make the action seem cramped and are only
suggestions, it may also just be easier to say Infantry, APSW, RFAC and HVC
ranges =
normal/4, HKP - normal/3, MDC and DFFG = normal/2 and missiles are
unaffected.

SYSTEM CLOSE MED LONG HEL 30" (if clear open ocean waters) 10" (if coastal
waters) 5" (if turbid estuarine waters)
RFAC/1  2"              3"              4"
RFAC/2  3"              4"              5"
HVC/3           4"              6"              8"
HVC/4           5"              8"              11"
HVC/5           6"              10"             14"
HKP/3           5"              10"             15"
HKP/4           8"              13"             18"
HKP/5           11"             16"             21"
MDC/1   4"              8"              12"
MDC/2   6"              10"             14"
MDC/3   12"             18"             24"
MDC/4   15"             21"             27"
MDC/5   18"             24"             30"
DFFG/1  2"              4"              6"
DFFG/2  3"              6"              9"
DFFG/3  4"              8"              12"
DFFG/4  5"              10"             15"
DFFG/5  6"              12"             18"
SLAM* 12" 24" 36"
GMS/L*  36"
GMS/H*  48"
IAVR* 4" APSW 4" Militia 1" Line 2" PA 3" *Assumed to be modified designs
suitable for use underwater.

Mobility and terrain effects: It is assumed here that all battles are
undertaken in good to mild weather if in shallow, surface weather means little
if at depth. However, large internal waves (waves or currents along depths
where there are sudden
changes in water density, temperature, chemical make-up) can be quite a
hazard. CFEs can only act as normal for 8 turns (in DS), before it must
surface to 'breath'. Movement is slightly modified compared to land:

Unsuited Inf - BMF: 2
EASY = With strong current NORMAL = Flats, below wave breaking zone POOR =
Kelp forests, reefs, rough, mountainous,

DIFFICULT = In wave zone or turbulence, against strong current IMPASSABLE =
Deep water (vertically), very strong currents, high turbulence, frigid waters

Power Armour/ Cav/Scooters - BMF: 6/8/6
EASY = With strong current NORMAL = Flats, below wave breaking zone POOR =
Kelp forests, reefs, rough, mountainous, wave zone or turbulence, against
strong current DIFFICULT = Deep water (vertically) if PA, very strong currents
if Cav, frigid waters if PA IMPASSABLE = High turbulence, frigid waters if not
PA, deep water (vertically) if not PA or if remain with mount (marine fauna
may usually descend at 'normal')

Amphibious Low/High-Mobility Wheeled - BMF: 4/6
EASY = Pebble flats NORMAL = Sandflats POOR = Mudflats, wave zone, against
strong current DIFFICULT = Low story kelp bed (like scrub on land), high
turbulence or rough if high mobility IMPASSABLE = High turbulence or rough if
low mobility, deep water, kelp forest, reefs, mountainous,

Slow/Fast tracked - BMF: 6/9
EASY = Pebble flats NORMAL = Sandflats POOR = Mudflats, wave zone, against
strong current, low story kelp bed (like scrub on land), high turbulence,
rough DIFFICULT = Kelp forest, reefs, mountainous IMPASSABLE = Deep water

Slow/Fast GEV - BMF: 12/15
EASY = Above water's surface IMPASSABLE = All else

GRAV - BMF: 15
EASY = Flats, NORMAL = Wave zone, against strong current, low story kelp bed
(like scrub on land), rough POOR = High turbulence, reefs, DIFFICULT =
Mountainous, deep water IMPASSABLE = Kelp forest

Slow/Fast/Attack Boats - BMF: 8/12/15
EASY = Flats NORMAL = Low story kelp bed (like scrub on land), rough POOR =
Wave zone (if amphibious), against strong current, high turbulence, reefs,
DIFFICULT = Kelp forest, mountainous, deep water IMPASSABLE = Wave zone or
shallows if not amphibious

Walkers (non-amphibious) - BMF: 10
EASY = With strong current NORMAL = Flats, below wave breaking zone POOR =
Kelp forests, reefs, rough, mountainous, wave zone or turbulence, against
strong current DIFFICULT = Very strong currents, high turbulence IMPASSABLE =
Deep water (vertically)

Walkers (amphibious - have thrusters to allow 'swimming') - BMF: 10
EASY = Flats, with strong current NORMAL = Wave zone, deep water (vertically),
against strong current, turbulence POOR = Kelp forests, reefs, rough,
mountainous, very strong currents DIFFICULT = High turbulence IMPASSABLE =
None (assuming pressurised for abyssal depths, if not then some depths would
be a barrier)

Many more vessel types will gain the VTOL 'pop-up' ability, these would
include GRAV, boats (subsurface ones), Infantry, Cavalry, Scooters and PA and
amphibious walkers.

Scooters: Scooters are size 1 vehicles, but they are an exception to the
'riverine' armour rule and may carry armour of class 1.

Explosive effects: If a hit is scored by any type of missile or explosive
artillery system or if any vehicle is destroyed by a boom counter (regardless
of the weapon type that caused it) then every element (whether of the same or
different unit, friend or enemy) within 3" must roll a D6 on a 6 they too have
been hit (the shock wave from the explosion has had a knock on effect). For
every hit pull 2 chits, all specials (except firer's systems down) DO count
against vehicles.

Close Assaults:
All unsuited (i.e. non-PA) infantry have an addition +1 to their threat
levels.

DFO: Depth charges are assumed to be a type of the deadfall ordinance, in this
case DFO's may be delivered by surface vessels not just aerospace vehicles.
For a surface vessel to drop DFO they move as normal and must place the fire
marker at some point along that path. However do not forget that anything
(including surface ships) caught within 3" will roll to see if they take
damage, so be careful where you drop it...

Smoke (well ink really): Well smoke itself would be useless you could use
'ink' instead with no change to the rules as they stand.

Wildlife: There are MANY possibilities here, but just to kick the ball off,
here are a few ideas.

Casualties in the water can breed their own threat via large aquatic
predators. A number of explosions would chase them off (so they're less likely
to hang around if there's lots of 'missiles' flying), though tonnes of dead or
stunned fauna floating around may well be an obscuration issue in itself.
However, if vehicles and squads are being removed be direct fire than there
may well be large predators and scavengers attracted to the site. Things that
would threaten vehicles would have to be very large, so they could be any size
(but I wouldn't give them armour beyond 1 or 2 regardless of size) and I'd let
them pull 5 chits (it needn't even be due to teeth etc, just getting hit by a
whale's fluke could cause big damage to
many vehicles). Smaller (more earth-sized) predators could threaten
unsuited infantry, cavalry or scooters. I'd give them a BMF of 8-10,
they must be in contact to attack and they pull 3 chits if an individual, 4 if
in a pack. For all of these only numbered chits would count, all colours vs
unsuited infantry, red only against vehicles and PA.

Swarms of stinging wildlife (like jellyfish on earth) could also be a threat
if encountered in swarms. These would move with the currents and if they end
on the same spot as a unit then they will smother it. Vehicles and PA don't
take damage, but they are hampered and must spend an activation doing nothing
but moving slowly to clear their hulls. Unsuited infantry suffer an attack,
the jellyfish pull 2 chits and all colours count.