LOL. The 'Juno' and 'Flash' are my top two favorite 'gunpods'!
-=Tips for the part before the stinkin' sub=-
Anyways, the part before that stupid submarine........
Try hanging around in the area by the score/multiplier counter. My dad, who isn't that good at games, beat that level by doing that. And considering I used to get killed a ba-jillions of times there, that's pretty cool. If you're feeling brave, at least have a cannon, flash, vulcan, juno, or anything good at killing masses of weaklings on hand.
-=Boss Tips=-
(starting from the first one)
(I'll list the german name, the translation according to a guide, and my nickname for it)
SPJ-15 "Greif" [Griffin] (Floaty Dude)
Shoot his head with a strong weapon. Not easy with him moving like an idiot.
SPKB-03 "Drache" [Dragon] (The Guy With a -BUTT- Cannon)
Shoot the claw with something that hurts. If you can blow the 'head' thingy that shoots lasers before the 'Dragon' flips over to use it, it'll end the battle quicker.
SKP-04 "Garnele" [Shrimp] (Jumpy Freak)
Shoot the blue-greenish colored thing with something like a grenade or flash. Or for fun, you can shoot off his 'claws' and watch him malfunction. Fun.
PGZ/L-03 "Spinne" [Spider] (The guy who ain't a spider)
Grenade/flash/juno to the head over and over. Annoying cuz he's so durable. Blow up the 'arm' things to A.) Dis-arm him B.) Increase your survival rate. Note his code number really stands out with the '/'.
SPKB-08 "Gecko" [no translation] (The REAL Spider, The Laser Freak)
His weak blue-green spot is half-protected by his legs. The flash or grenade does amazingly well. His weak spot takes up like, HALF his body!
PR-1 "Gustav" [none] (Tank, Yo-Yo Guy)
Use grenade. Out of the weapons that can fire backwards, the spreader is too weak and spreading, wasp isn't THAT powerful and doesn't always home(when on the top of your fighter), and the mosquito (secret weapon) is hard to even USE. If you don't like the grenade, use flash or juno. If a hatch opens and lets out mines, you can circle around him, and if done properly, he'll hit himself!
EU-46 "Salamander" [none] (Fishy, Lightsaber Tail)
Juno, juno, and more juno. Get it from the sub before this guy. Or just use a flash.
SPKB-04 "Sturmvogel" [Stormbird]
Blow up his 'shield' with a flash/juno/grenade (the 'boss-killer' guns, heh) . Then shoot the blue-green top-left corner after he gets his armor with anything powerful.
SPKB-06 "Ausf A Gestell" [?] (MONKEY!, Lightsaber Fingers)
Hit his head, but YOU'RE NOT ALWAYS ABLE TO HIT IT, VERY ANNOYING. Aim for whatever you -CAN- hit. Use the 'boss-killer- weapons, you can get a grenade right before the battle and a flash during battle. Every time you knock this guy down, he'll throw a crate at you, containing a weapon.
--CRATE WEAPON LIST--
1st-Wasp (Buzzzz-BOOM)
2nd-Wasp (again)
3rd-Riot (zappy)
4th-Flash (w00t)
5th-Cannon (Bang, ka-click)
6th-Blade (Star Wars anyone?)
7th-Spreader (Shotgun day)
8th-Hedgehog (The 9th place to knock him down KILLS him)
--Partial List of 'hit spots' for knockdown--
-Arm armor
-Arms! (he kicks them at you now that he's unARMED

)
-Hands
-Head (the two head ARMOR parts, not the HEAD)
SPKB-7 "Ausf D Duerer" [?]
The 'boss-killer' weapons again. Blow off the guns and watch out when yellow lines show up. Move between the lines. If his head stupidly glows blue, watch out for triangles that shoot. He also looks like a slipping skier when he dies.
The SpaceCraft Thrusters
Shoot the thrusters with a 'boss-killer' (geez, these guns are like the Halo pistol, they can do well in most situations). Watch out for enemies tailing you and don't get fried by the thruster. Don't take too long or you'll get 'Ending 2'! That's a game over!
SS-01 "Schwarzgeist" [Black Ghost] (The Thing That Looks Like it can BLOW UP EARTH)
Blast the saucer thing. Use the flash or juno. Grenades will fall downwards and hit the bottom areas instead. If you see a little saucer raise from the bigger one, blast it and you'll fight the 'Jelly fish'. There's the yellow laser thing again too, and this level IMO has the best music. It's called (at least from where I heard) 'Thermosphere'.
Jellyfish Thing (The Screen Flooder)
He shoots like crazy and rushes at you, but you can kill him with a vulcan without too much problem, except for having to not get hit. If you die to this guy, you'll start again at Black Ghost. Killing Jellyfish gets you a secret bonus (w00t, extra points).
Hyperion UCS Mk.XII (the one that tells you stuff while the score screen is on!)
If you wanna be a wuss during the actual level, set speed to max and fly up the whole time. During the battle, you'll want to set speed up anyways. Again, use the 'boss-killers'. Enjoy the scene (Spoilers if you haven't beaten the game yet) where the Hyperion crashes into a planet/moon (I forgot, haven't played Einhander in a little while). Enjoy the ending.
EDIT: Referance Source:
http://www.gamefaqs.com/console/psx/game/197217.htmlThe 74k guide on the above link.
Any other things needed?