Quick clarification

[Bosefius]

Someone asked if a mech that is prone in Level 1 water can be hit by a DFA. My answer is yes because the rules state that only submerged aquatic vehicles (and airborne units) cannot be targeted by a DFA.

Am I mistaken?

[Frabby]

Your line of reasoning, however, would suggest that a 'Mech can be targeted with DFA at any depth, which feels wrong.

A prone 'Mech is, to the best of my knowledge, zero levels high (not one), so the DFA attack against a prone 'Mech in lvl1 water is an underwater attack.
I seem to recall a ruling (but of course cannot find it in a quick search) to the effect that you cannot attack through the waterline. That would seem to preclude the DFA attack.

(Back in the day, our group argued if there can be level zero water on the maps - many rivers on official maps have no depth levels mentioned. We reasoned/house ruled in our campaign that they're level zero water which does force pilot rolls, extra MPs and all the other drawbacks associated with entering a water hex but doesn't grant any benefits associated with standing in lvl1 water. Never found out if that's the official way to read the rules.)

[Bosefius]

Your line of reasoning, however, would suggest that a 'Mech can be targeted with DFA at any depth, which feels wrong.

A prone 'Mech is, to the best of my knowledge, zero levels high (not one), so the DFA attack against a prone 'Mech in lvl1 water is an underwater attack.
I seem to recall a ruling (but of course cannot find it in a quick search) to the effect that you cannot attack through the waterline. That would seem to preclude the DFA attack.

(Back in the day, our group argued if there can be level zero water on the maps - many rivers on official maps have no depth levels mentioned. We reasoned/house ruled in our campaign that they're level zero water which does force pilot rolls, extra MPs and all the other drawbacks associated with entering a water hex but doesn't grant any benefits associated with standing in lvl1 water. Never found out if that's the official way to read the rules.)

That was my initial thought except you can attack through waterlines and you can also jump into Level 1 water.

[Frabby]

That was my initial thought except you can attack through waterlines

You can? Can you provide a source please? (Honest question, as my understanding of the rules was that this was explicitly not allowed.)

[nckestrel]

total Warfare p144 for Physical attacks has a section on water.
if the attacker is in..
Depth 1 water: specifically says the mech cannot make charge or death from above attacks.
Depth 2 water: has a list of allowed physicals that does not include death from above.

p149 under Death From Above says you must jump in to the hex, but stop just short.  (whatever that means rules wise).
It then says specifically submerged naval vessels cannot be the target of death from above attacks (though why mention that rather than just no submerged unit may be death from aboved?)

Ah, "for purposes of determining LOS, the attacking unit is considered to be in the air above the hex, standing one level higher than the target hex or the level of the hex the attacker occupies, whichever is higher."  (wait, isn't that the same hex??)  If you are one level above a prone 'mech in level 1 water, the attacker is at level 0, or the surface of the water.  And surface units do not have LOS to underwater units (TW p102 Water."This means that units above the water, such as hover or WiGE vehicles, never have LOS to a submerged unit, even if they occupy the same water hex.") 

If the target was prone in level 2 water, then the attacker is in level 1 water.  Has LOS, but then p144 blocks death from above.

[Frabby]

That clears it up. Thanks nckestrel!  O0

[nckestrel]

I don't know if that is the final answer, just what I found.  :)

[Bosefius]

To be clear, no LOS is the ruling, correct? At least so far.

[nckestrel]

I didn't verify that physicals need line of sight.  Too worn out to go check now (one of those I just usually assume, but that can always cause problems).

[Frabby]

Addendum: Someone asked pretty much the same question in the TW forum:
Line of sight, submerged units and physical attacks

Worth watching for what the answer will be over there. ;)

[Bosefius]

Addendum: Someone asked pretty much the same question in the TW forum:
Line of sight, submerged units and physical attacks

Worth watching for what the answer will be over there. ;)

That's the same reason I posted, LOL

[Bosefius]

I didn't verify that physicals need line of sight.  Too worn out to go check now (one of those I just usually assume, but that can always cause problems).

Further with what you posted about a lack of LOS, page 101, first line of "Line of Sight" states you must have line of sight to declare an attack. Combined with your posts this should preclude the attack since a submerged mech is hidden.