Episode 1

Agreed.

So are we all swimming down and readying actions to javelin the hell out of any that come close?

Is readying an action a hold over from Pathfinder and not actually a thing in 5e?

Does anyone else type out the formatting brackets like I do, and every damned time type "occ" as in Rifts "Occupational Character Class"

Cool. Good comms and I can picture the strategy.
I know you are envisioning roughly a circle, cutting off the lower angles with the floor, and at the same time you are trying to give a little extra protection to the special resources, Hinka and Rutcranna. In the water, it doesn't have to line up exactly linear and rigid on the spacing. I think there is room to have the protected pair slightly inset, so that the protectors can hopefully waive off and intervene on attacks in their direction, but also ensure that Hinka/Rutcranna can still get in some shots of offense when possible as well if the situation allows it.

So I am moving forward with everyone dropping elevation as the Move Action, getting in position. I think it was a bit of a close call for little Hinka because he was the one furthest up when the bad news started becoming clear. I kind of picture it that Bryn and Kray kind of had to grab that guy and sort of pull/push him down to get him to position just in the nick of time before he could have gotten nabbed by a quick Deep One. Pays to win Initiative! They would have loved to have started off with a Grapple and swim away program with Hinka Red-Light during Top of Round 1 if they had prevailed.

So after Movement, or maybe a little bit During Movement, some of you have already started blasting which is great. On that, I'm just going to kind of roll with it that you are picking the targets that are within the Normal Range to avoid Disadvantage.

Ox, on your commentary of the band launch Javelins, that was a good review, but I did make one more entry adjusting Range Underwater to 30/45. Yeah, I did cut back that range length - just didn't seem realistic that these would go as far as a Javelin thrown on the ground in normal air.
So up to 30 feet - all normal Attack. Use DEX mods for Attack and Damage.
31-45 feet - Attack at Disadvantage. (it is not an auto miss like most underwater missiles after norm range)

There are some opponents in the normal Range already, so I'm going to be writing some Attack results from that.

I'm sneaking off a bit at work to make some entries to catch up. If I can't get it all right away, will try to follow up late tonight.

CB, love that Champion 19 Critical. Good to see that sending an impact. I had kind of intended for the Tcho-Tcho critical boost die to only apply with the band launcher, because of the specialized tailoring of the system to water combat, but I'm good with letting the full damage apply this time even with the fatboy manual heave-toss because it is a really cool scene and don't want to pass up on the Critical exploit.

X, I see the Great Weapon Fighting reroll on Damage, but I'm not convinced that it applies here. The javelin has neither Versatile nor Two-Handed property. It is a one handed weapon and launched with an aiming mechanism. Right now, I feel like I have to record the 2 damage instead of the 6 unfortunately, but I'm still open to persuasion if you can make the case otherwise and tell me another way to look at it.

Hey, since I think I understand that Thorn has 2 Attacks per round, I feel like we can consider the second Melee javelin Attack in the temporary category of a Hold that can be released when the opponent comes into melee range.
Which that is pretty much right now. They will Attack at BR1, but go ahead and send your 2nd Attack of TR1 now, and let's say Thorn holds and then jabs that bitch out right as Fishy Guys is lurching forward for the strike.

Hey, just to be clear in advance just in case...
Underwater Javelins can be used as Melee weapons, avoiding Disadvantage for Underwater use, but the Tcho-Tcho launcher extra Critical Hit die will not apply to Melee Criticals.

Jabes, similar to entry to X above, you guys have Initiative. I understand Ivor's stance as a Hold Action, triggered by the approach of the enemy into melee Range.
So, send in an Attack as you want. I will consider it occurring moments before the opponent's Attack, at the end of TR1, just before BR1.

Ox, see above for Bryn's TR1 options. Fire launching a Javelin is possible or the strategy of Hold and then Melee Attack after enemy approach, similar to what we have set up for Thorn and Ivor above (I think, unless anyone gives a rebuttal against the idea).

Ox, I know that Sneak Attack is the every-round goal in the life of a Rogue, no harm at all in asking early and often, but I just cannot see how it would apply in this circumstance.

This is plain old approach and attack. You guys are using each other to guard flanking routes and cut down on some of the numbers of multiple opponents per each guy, but it's going to be a lot of toe-to-toe and multiple opponents each man, at least at the beginning.

We'll see as the combat starts rolling and maybe some positional advantages emerge or situational changes come up for exploitation, but right now it will just be normal Attacks.

You can do the Hold and then Attack, still at the bottom edge of TR1 if an opponent approaches (and they definitely do). So feel free to send that when ready.

On opponent strategy: some are coming in fast, some holding back, seem to be getting in optimal position for a flood of overwhelming barrage of opening attacks from as many angles as possible.

Fair enough. You are set up then for Javelin use as STR based, no-Disadvantage melee weapon in TR2 then.
X, you become the second player, joining CB, to talk the DM OUT of a player-advantageous rule interpretation. Touché.