Bsemanoff
New
Hi Scuba Board! This is my first post, so I’m excited to share. I rarely post on boards so this is a relatively new experience for me! Also not sure if this is the best category to file this post in… this is less of a question and more of an answer I found to a question I had. So here goes...
I‘ve been dry suit diving a lot lately… in fact its become the only kind of diving I do these days since I travel a lot for work, and I sneak in dives on the weekends… so i need a light exposure suit and one that dries quickly. And in general I’ve fallen in love with Dry Suit diving. Its defintely a different kind of diving.
That said, my old fins (a pair of Oceanic Manta fins) were not negatively buoyant enough. So I was on the hunt for the right fin with the right buoyancy… suprisingly theres little to no data on the actual buoyancy of fins. Mfgs make vague claims like “neutrally buoyant” or “the best fin for dry suit diving.” But I would think manufacturers of equipment used underwater would publish more specific data. And even the data they do publish tends to be inaccurate. So I tested 4 fins and wanted to share my results.
First to explain what exactly I did… basically I filled a big tall bucket with fresh water right to the rim (yes, this data will all be based on fresh water BUT at least the results are all relative to each other), then placed that bucket into a large tray that would catch any water that spilled over the rim, and finally submerged the fin into the bucket. I then measured how much water was displaced and calculated the fins buoyancy. I then weighed each fin and calculated the force of gravity on each fin and subtracted the force of buoyancy from the weight of gravity to get the net force. I did this with the Oceanic Manta Fin, Apex R3, Hollis LT and Hollis F1. Here are the results in fresh water:
Manta Fins Weigh 2.2lbs each and will feel like they weigh 0.4 lbs in fresh water
Hollis LT Fins weigh 3.5lbs each and will feel like they weigh 0.88 lbs in fresh water
Hollis F1 Fins weigh 3.8lbs each and will feel like they weigh 1.3 lbs in fresh water
Apex R3 Fins weigh 3.2lbs each and will feel like they weigh 0.69 lbs in fresh water
Hollis really misrepresents the weight of the LT. They advertise that the fin weighs 3lbs… when in fact each fin weighs 3.5lbs. Thats an extra pound total in the luggage… and if you’re trying to keep your gear back under 50lbs… this makes a difference. And when the conceit is the LT is the lightweight answer to the F1… you’d expect the weight difference of the fins to be greater than 0.3lbs.
That said, despite only a 0.3lb weight difference out of the water, the buoyancy difference is about 0.52lbs. Which can really make a difference when you’re trying to keep your trim in a dry suit.
Anyway, I had been searching for data like this and couldn’t find it… and it’s really helped me in making a decision about my next set of fins. I figured there might be others out there with a similar question.
I‘ve been dry suit diving a lot lately… in fact its become the only kind of diving I do these days since I travel a lot for work, and I sneak in dives on the weekends… so i need a light exposure suit and one that dries quickly. And in general I’ve fallen in love with Dry Suit diving. Its defintely a different kind of diving.
That said, my old fins (a pair of Oceanic Manta fins) were not negatively buoyant enough. So I was on the hunt for the right fin with the right buoyancy… suprisingly theres little to no data on the actual buoyancy of fins. Mfgs make vague claims like “neutrally buoyant” or “the best fin for dry suit diving.” But I would think manufacturers of equipment used underwater would publish more specific data. And even the data they do publish tends to be inaccurate. So I tested 4 fins and wanted to share my results.
First to explain what exactly I did… basically I filled a big tall bucket with fresh water right to the rim (yes, this data will all be based on fresh water BUT at least the results are all relative to each other), then placed that bucket into a large tray that would catch any water that spilled over the rim, and finally submerged the fin into the bucket. I then measured how much water was displaced and calculated the fins buoyancy. I then weighed each fin and calculated the force of gravity on each fin and subtracted the force of buoyancy from the weight of gravity to get the net force. I did this with the Oceanic Manta Fin, Apex R3, Hollis LT and Hollis F1. Here are the results in fresh water:
Manta Fins Weigh 2.2lbs each and will feel like they weigh 0.4 lbs in fresh water
Hollis LT Fins weigh 3.5lbs each and will feel like they weigh 0.88 lbs in fresh water
Hollis F1 Fins weigh 3.8lbs each and will feel like they weigh 1.3 lbs in fresh water
Apex R3 Fins weigh 3.2lbs each and will feel like they weigh 0.69 lbs in fresh water
Hollis really misrepresents the weight of the LT. They advertise that the fin weighs 3lbs… when in fact each fin weighs 3.5lbs. Thats an extra pound total in the luggage… and if you’re trying to keep your gear back under 50lbs… this makes a difference. And when the conceit is the LT is the lightweight answer to the F1… you’d expect the weight difference of the fins to be greater than 0.3lbs.
That said, despite only a 0.3lb weight difference out of the water, the buoyancy difference is about 0.52lbs. Which can really make a difference when you’re trying to keep your trim in a dry suit.
Anyway, I had been searching for data like this and couldn’t find it… and it’s really helped me in making a decision about my next set of fins. I figured there might be others out there with a similar question.
