TLR I'm creating this thread to see if the collective ScubaBoard "we" can come up with some DIY-able method(s) for weighting the new ScubaPro MFS Fins (SuperNova & S-Tek)
Background:
Off the shelf option(s):
DIY Concepts (since Scuba rule #1 - Don't hold your breath {for SP to do it for us}):
Next:
Background:
I recently obtained a pair of ScubaPro SeaWing SuperNovas.
I'm pleased that the "Large" size "Open-Heel" foot pockets seem like they will fit everything in my current stable of footwear
- Size 9 DeepSea 5mmm Safe-Sole Ergos (wet -warm, boat)
- Size M SeaSoft Ti Stealths (wet - quarry)
- Size 9W Altama Maritime Assaults (wet - wear to travel in)
- Size 10.5W Altama Maritime Assaults (dry)
I dove them for 8 warm-water dives in Cozumel (3mm suit with, 5mm soft-sole booties). They are buoyant enough to help with my sinky feet when diving wet.
Since they fit my full footwear range, I would like to be able to dive them dry as well. But they would need to be more negatively buoyant as my feet are somewhat floaty when diving dry. (Yes, I know, gaiters and ankle weights, but I'd prefer not to go that route.)
I would imagine that the ability to tune the net-buoyancy based on person/equipment/circumstances would be useful to a good number of "us".
I came back from my trip re-injured so I'll be out of the water for a while. Tinkering with diving equipment is the next best thing.
Off the shelf option(s):
S-Tek Blades
- I don't believe that increasing the net mass of the moving, cantilevered part of the fin is the optimal way to adjust buoyancy. I believe that it will reduce efficiency and "feel" vs weighting at the foot pocket area.
- (For me) Undetermined pros/cons of the greater angle, smaller blade, and flatter blade profile.
- I'd also have to buy them - $$
Wishful Thinking - ScubaPro, are you listening?
It seems to me the best way to deal with this in a "Modular Fin System" would be to have the ability to weight the foot-pocket section. I took a look at the existing structure of the foot pocket. It seems to me that it would be possible to put molded slots or recesses along each side of the fin, between the strap-mounting boss and the takedown-pin area. Even if each slot was 0.5" "thick" It would extend only trivially wider than the installed straps.
On my "Large" pockets, that looks like it could fit a 4"L x 1.5"W weight. Assuming that even on smaller pockets something on the order 3.5"L x 1"W would work. If weight plates were made from 0.25" thick 316L, they would have a volume of (3.5" * 1" * 0.25" =) 0.875in³. With 316L having a density of 0.289 lb/in³, each plate would be about a 1/4 lb (0.875in³ * 0.289 lb/in³ = 0.252875lb). With space for 4 plates (2 per slot, 2 sides), that would give configurable buoyancy on the order of up to a pound of reduced buoyancy at each foot.
Additional MFS Lock-plates could be used to retain the weight-plates in the slots for consistency.
DIY Concepts (since Scuba rule #1 - Don't hold your breath {for SP to do it for us}):
Spring Straps (Wahh - Waaa):
- I pulled my spring straps off of my OMS Slipstreams with high hopes. They will fit the two rear pin positions on the strap-bosses - easy-peasy.
- However (allowing for an equivalent length version) the Spring straps are about 0.1lb heavier on the scale. Even allowing for density differences, we are probably looking at around 2-3 oz (0.125-0.1875lb) per fin buoyancy reduction at best.
- Better, but not enough by itself to make a significant difference.
Inside the pocket at the Toe:
- Could be molded lead - dense, easy and cheap to produce at different "thicknesses" (within limits) once the molds are made
- Drain holes can pass a 1/4" "bolt" for alignment/retention. (Some outside spreader plate would be needed)
- Not a huge volume and it is going to be very dependent on the user/pocket- size/footwear combination. (Since my feet are fat/wide, not long, there is a good amount of room ahead of the boots in the foot pocket, especially with the larger soled boots)
Outside the pocket at the Toe:
- Could be molded lead - dense, easy and cheap to produce at different "thicknesses" (within limits) once the molds are made
- Drain holes can pass a 1/4" "bolt" for alignment/retention. (Some inside spreader plate would be needed)
- Can surround (cap) the toe-box and around the webs between the toe and the arm-sockets to provide a pretty good volume without extending above or below the arm sockets
- Length is more limited with S-Tek blades as the blade sits closer to the toe-box
- Impinges on the toe-box to blade water channel - unknown hydro-dynamic implications
Next:
- What do you all think?
- Other Ideas?