Santi BZ 400 extreme

[coldwaterdufus]

I'm getting tired of being cold. I'm now trying longer dives in fairly chilly water. I dive in temps down to 37 F. Average temp here is mid 40's. I'm looking at the Santl BZ 400 extreme heated thermal with gloves, canister , the whole set up. I currently dive a Bare Super high loft thermal under a Bare Nexgen. It's been great for 10 years now, but lately , I need something better. Any thoughts about the Santi. I hear it's quite floaty, sorta wondering how much weight I might need to add. I realize I'll only sort that out in the water on dive 1. Maybe someone has an idea on that subject out there . Thanks

 

[grantctobin]

I'm getting tired of being cold. I'm now trying longer dives in fairly chilly water. I dive in temps down to 37 F. Average temp here is mid 40's. I'm looking at the Santl BZ 400 extreme heated thermal with gloves, canister , the whole set up. I currently dive a Bare Super high loft thermal under a Bare Nexgen. It's been great for 10 years now, but lately , I need something better. Any thoughts about the Santi. I hear it's quite floaty, sorta wondering how much weight I might need to add. I realize I'll only sort that out in the water on dive 1. Maybe someone has an idea on that subject out there . Thanks

Try before you buy if you can. What durations are you running in these temps?

With that many watts in a suit/gloves, you'll likely want a heat controller. @tbone1004 the resident expert, but if starting again I would get a Halo3D, Scubaforce or Exo2 vest, SmartTrex heated gloves and socks, SiTech Vega Valve (or LM Valve, but half of the ones they send out seem to have a machining error), LightMonkey Canister w Pitkin Lid (or their Pitkin Controller) OR UWLD canister+heater controller. @rjack321 also has some great opinions on this sort of thing.

Keep in mind, with a BZ400 heated suit and gloves, you'll be sucking up 110W suit, 36W gloves = 146W. A LM 20aH canister is ~230wH or ~1.43Hr on full blast when you add 10% to the 146W figure. That much heat will likely cook you, so you need a way to bring it down (rather than only having on or off). This brings you to a Pitkin head (on/off flickering decreases power) from Light Monkey, a Pitkin Controller (standard E/O cord and battery but on/off power decrease is regulated in the controller) from LightMonkey, or going w the UWLD pack. If you're going to run gloves and suit, you realistically need a Tall UWLD canister or a 20aH + LM canister.

Few things to keep in mind:
-Don't start the dive warm and end cold (bent)
-Don't be very cold and then blast heat (bent)
-Don't rely on heat as your only thermal strategy (battery dies then hypothermia or bent)
-Gentle heat throughout dive and then ramping it up towards deco is far safer
-Temperature control is far better than flicking on and off switch when you get cold
-There's no such thing as too big of a battery

 

[Matt Vandercook]

i dive the 400xtreme, with my trilam drysuit i need 28lbs in salt water with a steel 100cf tank. they aren't that much more floaty than DUI thermals (i haven't tried other manufactures thermals so can comment on those). I've heard great things for the 400x and a heated vest under, also has the benefit of reducing your power consumption

 

[RVBldr]

Just started diving a standard BZ400 and found I needed to add about 6 lbs to start - it's floaty for sure but I understand that over time it will compact a bit. I also run that with the BZ200 heated vest. With my old 4E Arctics, I was going thorugh an entire 10A battery with the heat here in Seattle at 46F, but with the BZ400, I'm down to only using the heat for a couple minutes it seems for 80 minute CCR dives locally.

 

[rduquesnoy]

I have done about 10+ dives now with a BZ400 and I notice it is starting to become a bit less floaty.
With my suit (Santi E-Lite+) canister light, Jetfins, D12 tanks and a Carbon backplate (!) I need to add another 17 lbs in fresh water. Think I could remove some but for now this works fine also with the tanks almost empty.

I tend to get cold pretty quick but that is not the case with this undersuit. Heated gloves may be a nice option though as my hands are the first to get cold (after 45 minutes or so).

 

[johnkendall]

The suit will not cook you. On many dives I'm running the BZ400 heated, and adding a 200gr Heated vest as well. I don't see any need to drop the power going into the suit. You either want the heating, in which case leave it turned on, or don't (so turn it off). The BZ400 is significantly more insulating that a Halo 3D, and is my go-to suit for colder water.

HTH
John

 

[coldwaterdufus]

Gentlemen, Thanks for the input. Grant, I appreciate the notes at the end . I've read about the connection re getting bent and heat. Still learning. My current max duration in 38 F is about 40 minutes. I am pretty chilly though. I'm always warmer on the second dive than the first, same duration. Getting acclimatized, I guess. ( maybe brain dead ) Matt/RVBldr, I was going through my weightings. I was guessing at adding 6 lbs to my current set-up, I'd be at 30 lbs in salt with my steel 100's, very close to your numbers. Good confirmation. Angel Fish, do you know how much you needed to add for the BZ 400 versus your old setup, everything else being similar. John, good comment re the BZ 400 being your go to suit. Makes me think I'm on the right track.

This might cause a bit of a discussion, but I need to ask it . What are people's thoughts about internal batteries ( inside your Dry suit ) versus canisters. A few people I know have the internal ones, I'm leaning away from them. This is based on very limited knowledge but looking at it from a safety point of view. My general impression is the internals are a little less expensive .

 

[coldwaterdufus]

Grant , I hadn't got to the point about the on/off switch on the Santi. I'm actually glad you pointed it out. Made me think about it. I do like the idea of a lesser amount of controlled heat over the whole dive . Gonna be hard to try it out before I buy, especially with all this other %$#@ going on

 

[michael-fisch]

Next problem you'll have with the BZ400.
It's a thinsulate suit. Those in the know do the following:
Buy new. Dive it until the flies avoid it. Then wash it once and post it in Ebay as "washed only once according to Ebay rules", since a washed thinsulate is nowhere near as warm as an unwashed/new one. Now buy a new one.
or
Buy a suit that doesn't use thinsulate, Weezle comes to mind, and use it with heated undies (I use Heizteufel) and a controller.

Michael

 

[Jack Hammer]

I'm not a fan of internal batteries. Basically I just don't trust them and prefer having the ability to disconnect them if ever needed.

I use the heated Santi vest under my bz400 (non heated) powered by a 160wh UWLD battery pack and controller. Normally in 4c/39f water I run it on the lowest setting (20%) during the dive and adjust as needed for deco. Pretty rare to get it above the 3rd (60%) setting as it gets pretty warm. full power is too hot and very uncomfortable.

Voltages matter with whatever heating and battery setup you go with. An 11.1v pack wont make as much heat as a 12v pack. The UWLD is a 18v pack that drops the voltage to 12v so it gives consistent heat output even when the pack is almost dead.