Buoyancy Question w/ New Fins

[howler93]

Hey folks!

I have a new pair of Hollis F-1's on their way...hoping I could get em prior to my AOW course comin' up. I've read a ton on them, and although I'm confident I made a good decision on the purchase, I have read that they tend to be fairly negatively buoyant.

My question is this:
If 99% of my diving will be in warm, salt water...wearing a shortie or 4/3 full wetsuit...should I anticipate trim problems with such "heavy" fins?

Any advice would be appreciated! Of course, if my LDS carried these fins, I would have tried them out first. Alas, I don't have this luxury

Thanks all!

Howler

 

[g1138]

I used to use flexible paddle fins that were slightly negative. Then I switched to Jet fins which ARE negative. I think I remember hearing that Hollis and Jet fins are roughly the same weight, size for size.

As long as you hover with your legs bent, you shouldn't have trim issues. You may need to toy with your body position a bit since the fins are weighted differently. But it shouldn't be something drastic like switching to a dry suit or buying new neoprene.
When you're cruising the hydrodynamics of the water should keep you in line for the most part. I think hovering will be the only time where you may find your trim is effected by your new fins. It can be corrected without changing your weight set up.
Try taking them for a test drive in the pool before your first adv dive. It'll make you much more relaxed when you're in the ocean.

Here's how you should look roughly. Your legs may be bent more away from your butt if you still feel feet heavy. A key thing to remember is if you feel yourself bending your legs and you're still feet heavy, chances are you're bending them too much.
[video=youtube;JlUjnXBzNlc]http://www.youtube.com/watch?v=JlUjnXBzNlc&feature=related[/video]

 

[Peter_C]

Sometimes a weight pocket on the top strap of the BC or in upper pockets on non BP/W type BC's helps keep the head down and feet up too. First though try bending the knees. Of course this lends itself more to frog kicks. Learn to use the fins as they are nice fins, and should serve you well.

 

[howler93]

g1138,

thanks for the advice. Another question along these lines: I've seen LOTS of dive video's showing divers with their hands outstretched in front of them. Is this a DIR technique? Wouldn't this increase drag somewhat compared to having your arms tucked in under the belly? All newb questions I know....but I'm not afraid to ask them! Thanks in advance,

Howler

 

[rongoodman]

g1138,

thanks for the advice. Another question along these lines: I've seen LOTS of dive video's showing divers with their hands outstretched in front of them. Is this a DIR technique? Wouldn't this increase drag somewhat compared to having your arms tucked in under the belly? All newb questions I know....but I'm not afraid to ask them! Thanks in advance,

Howler

You're usually diving with your arms out in front of you because your light is on your left hand, and it's there all the time, not just on night dives. Other than that, it doesn't make much difference, although you will be able to feel your trim wants to change when you move your arms from forward to tucked under your belly,

 

[Jim Lapenta]

The Hollis fins are designed to be neutral in salt water. They end up being about a pound neg in fresh. I have been diving them in both for three years and can attest that it is pretty much correct.

 

[DivemasterDennis]

In a word, No. No worry. If you have ggod buoyancy contral and hovering skills, you will have no issue at all.
DivemasterDennis

 

[howler93]

Thanks for the replies, everyone! They arrived today...wow these things are beefy! Glad to hear that the buoyancy shouldn't be too much of a problem with them, but I do have another question about fit, since this is the first time I've tried on an open heel fin. The f-1's seem to have a pretty roomy "foot box" (for lack of a better term)...but the spring heel straps seem to hold me in there pretty nicely. I don't plan on wearing booties much- if ever. How much space/movement is acceptable in the footbox? Thanks!!!

 

[g1138]

howler93 Hands in front of you will create some drag when you're crusing with flutter kicks. If you're hovering or frog kicking and not in any rush to go anywhere super fast, then it's not an issue at all. When you're cruising with flutter kicks though, your trim will usually level out due to the water rushing past you, so at that point "DIR positioning" isn't even needed.
Also rongoodman made a good point about the light placement, something I never even thought about.

 

[howler93]

I'm unable to dive with the new fins for awhile, but if they turn out to be a little negatively buoyant, would wearing 3mm neoprene booties help some? I know the f-1's were designed with dry-suit divers in mind, but that won't be happening for me any time soon. I think booties will help take up some of that ample footbox room too. ANy thoughts? And any good bootie recommendations? Thanks!

Howler