This is one of those situations maciejmad, where the ReadMe file helps. Of course, the info is buried in the file though. I have a sheet printed out with some of the ways to complete missions and objectives. This is from the ReadMe though:
"TWO SPECIAL MISSIONS- PHOTO RECON, AND LIFE GUARD DUTY
PHOTO RECON: You will receive photo Recon missions in campaigns
via a radio transmission. In addition to the radio message a red "T" icon
will appear on the chart screen over the facilities to be photographed.
In order to successfully complete a Photo Recon Mission the sub must
move close enough to the target area. A "red" light, located in the
TBT or Periscope viewing area will indicate the sub is close enough to
take a picture. The "TAB" key is used to take the photograph. The
user will know the mission is accomplished when the "T" icon
disappears from the chart screen, which will be accompanied by a voice
and text message stating "Mission completed, sir." Scoring - Each
completed Photo Recon mission is worth 500 points at the 100%
realism setting. NOTE: Photo Recon missions can only be accomplished
during daylight hours. It is best to remain completely zoomed out (1x)
in order to locate the area that needs to be photographed.
LIFE GUARD DUTY: Like the Photo Recon mission, in campaigns,
the user will receive the orders via a radio transmission. As with the Photo
Recon mission, a red "T" icon will appear over the port that will be
bombed by American aircraft. The user can watch the airstrike in
progress while sitting off the coast of the target area. The bomber
group will show up on SD radar, and on the chart screen. After the
airstrike is finished, blue triangle icons will appear indicating the
approximate location of the downed pilots. When the pilots are
spotted the user will receive a voice and text message stating "Downed
Pilot spotted". As the sub closes within 200 yards of the downed
aviator "We're close enough for a rescue, sir!" voice message and text
message will inform the user that the pilot can be extracted. At which
time the sub must slow down to 5 knots or slower and then hit the "E"
key OR the sub can run over the pilot in order to pick him up.
Scoring- each pilot saved is worth 200 points at 100%. NOTE: Pilots
can only last a limited time in the water before being captured or
succumbing to the elements. So it is entirely up to you if one of
America's valiant sons resides with NEPTUNIS REX in his watery domain
or perishes in a prison camp.
SUB VS. SUB:
Sub vs. Sub will be encountered in the campaign as well as single
scenarios. There are three types of subs, all of which can be seen in
the ship ID book under PATROL CRAFT. NOTE: In single scenarios if the
enemy is elite, the player may find that they are being stalked first.
When firing a torpedo at a Sub do not forget to adjust the depth of the
torpedo using the TDC."
... and remember Jim, if you or any of your Impossible Mission Force are injured or captured, the Secretary will disavow your very existence...