Pyramid #3/26: Underwater Adventures

[Kromm]

I often hear a lonely cry in the fog: "Where are the rules for underwater action in GURPS?" Well, the newly released Pyramid #3/26: Underwater Adventures is a good jumping-off point. It wades right in with an article that gathers all of the existing rules for aquatic adventures in one place and updates them for Fourth Edition. Then it deluges you with opportunities to use them: a decidedly creepy sunken wreck, a mysterious underwater monument, a race of vengeful octopods, a tale of mad science involving a time-lost Nazi sub, and an undersea hotel that plays host to intrigue and political machinations. No matter what your campaign's genre, if it has oceans, then you're sure to find yourself immersed in this issue.

[Stripe]

If Kromm makes one more pun -- ONE MORE -- the baby seal gets it: http://1.bp.blogspot.com/_j6rpUV1oUW...p-seal_359.jpg

Despite being drown with puns, t'will order when I get a chance. My day went swimmingly and it would be nice to relax and take a dip into a good book to end it. Though I'm showered with bills, the price of a Pyramid is always worth the content.

[Christopher R. Rice]

Originally Posted by Stripe

If Kromm makes one more pun -- ONE MORE -- the baby seal gets it: http://1.bp.blogspot.com/_j6rpUV1oUW...p-seal_359.jpg

Despite being drown with puns, t'will order when I get a chance. My day went swimmingly and it would be nice to relax and take a dip into a good book to end it. Though I'm showered with bills, the price of a Pyramid is always worth the content.

[morbid humor] What you don't like to go clubbing? XD [/morbid humor]

While the bit on fighting underwater is short, it's also concise and easily remembered. It has to be one of the coolest things to come out in Pyramid in a while. It will be put to immediate use.

Ghostdancer

[Trachmyr]

The Table for the Bends is a bit confusing... I don't understand how the saturation time is supposed to work. I'd appreciate some clarification.

Also, dropping the -2 penalty on "C" attacks seems a bit generous... likewise, do amphibious/aquatic characters no longer get a reduction on attack penalties?

----------------

Great Issue!
Will deffinately put it to use,
-Trachmyr

[Dinadon]

Originally Posted by Trachmyr

The Table for the Bends is a bit confusing... I don't understand how the saturation time is supposed to work. I'd appreciate some clarification.

It's time it takes to become fully saturated with nitrogen. If you've been down at the depth for that length of time, then you need to use the value given for decompression time. If you haven't been at that depth for that length of time then your decompression time will be shorter.

Presumably you can take the time you have spent at given depth, determine what percentage of the saturation time that is and then apply that percentage to the decompression time.

[Kromm]

Originally Posted by Trachmyr

Also, dropping the -2 penalty on "C" attacks seems a bit generous...

Not really. Once you're so close that you're in bodily contact – and that's what Reach C means – there isn't enough water in the few mm of space between you and your opponent to behave differently from air or vacuum. You might be inconvenienced by your need to swim at the same time, but that isn't a given; that's covered by limiting your combat skills to your DX-based Diving Suit or Scuba skill, as applicable, unless you're Amphibious or Aquatic.

Originally Posted by Trachmyr

likewise, do amphibious/aquatic characters no longer get a reduction on attack penalties?

See above. The penalties in this article are purely for fluid drag. Your bodily adaptations don't change how that works . . . being a merman doesn't make a 10' pollax any more sensible a weapon underwater. The penalties removed are those addressed by personal adaptation. Here, this means that you're not relying on Diving Suit or Scuba underwater, so your combat skills aren't limited to those levels. That, and you have full Move. Those are pretty big advantages all on their own.

The idea that the large penalties for fluid drag are included in the penalties eliminated by Amphibious is a common misconception only. Amphibious doesn't project a force field that sheathes your weapons and renders them frictionless.

[sir_pudding]

Shouldn't thrusting weapons suffer less drag than swinging weapons?

[RogerBW]

Originally Posted by Dinadon

It's time it takes to become fully saturated with nitrogen. If you've been down at the depth for that length of time, then you need to use the value given for decompression time. If you haven't been at that depth for that length of time then your decompression time will be shorter.

Presumably you can take the time you have spent at given depth, determine what percentage of the saturation time that is and then apply that percentage to the decompression time.

For gaming purposes you could do that. In real life it's a whole lot more complicated - last time I checked, the smart modellers were using twenty separate "compartments", each of which had a different nitrogen uptake rate and a different release rate (and each of those rates is roughly exponential, so they have half-lives rather than straight linear rates; mathematically it's like Newtonian cooling). If in doubt, extend decompression time.

Or of course you could use real dive tables - the US Navy ones at least are available on-line. For links, see Wikipedia "Dive tables".

As a GM rather than as a diver, I find it's usually more important to answer the question "can I do this dive without decompressing at all" than "how long will decompression take".

[Bruno]

Originally Posted by sir_pudding

Shouldn't thrusting weapons suffer less drag than swinging weapons?

Shouldn't a trident suffer more drag than a basic spear?

[sir_pudding]

Originally Posted by Bruno

Shouldn't a trident suffer more drag than a basic spear?

Yeah, but I'm not sure how that's relevant. I can see that falling into game-able abstraction more than I can see the difference in drag between a halberd swing and a thrust falling into it; which (unless I'm missing something) it has done so.