Thanks for doing that. If you had lost that fin we would have sent you another.I got my first dive in with the fins yesterday at Blue Heron Bridge. @landonnin1 was kind enough to capture video as soon as we got in the water. We had quite a large group of divers (7), 6 of which are scubaboard users. The plan was to get in the water around 12pm, and we had to arrive early for parking. This gave us hours to talk about whatever. I brought out the fins for show and tell. Everyone was curious and wanted to get an opportunity to hold a fin. I pulled the spines out a couple of times and let everyone see the spines.
Show and Tell:
Initial comments from the group:
What do they do?
They are heavy.
Why are they shaped that way?
I showed how the green spines don't flex one direction and explained how you can mix spines to customize flex. This concept seemed to intrigue everyone. A couple of people pulled their fins out and told stories, good and bad. I talked about how you could pull the spines out and roll the fin up for travel.
My thoughts:
Yes, they are heavy. I don't know if they are any heavier than the Hollis F1. I couldn't dive the F1's because they made me ankle heavy, so I was concerned about this going in. They were not that heavy underwater, and I'll speak more to this later. They definitely have good propulsion. The fins felt awkward at first. The medium springs fit well, maybe too well for my size 11, and my foot was hurting after about 45 minutes. I think this could be solved with a large spring. The foot pocket, otherwise, fit like a glove. The ability to adjust the spring would be nice, which is an option on the fins I normally use (Dive Rite XT). Occasionally, I had the feeling that I kicked something or someone, but I think it was the spines all engaging a limit at the same time. I had no trim problems. One annoyance with the shape of the fins, occasionally I'll get my fin caught up in my dive flag rope between my legs and it was extremely difficult to get the rope back to the other side because it would catch the shape of the fin where the spines insert. Maybe an angle adjustment would solve this. To get my foot out, I would have to roll to my back. I will try the fins again with anther colored spine, but I need to do something about the spring tension first. One of the biggest surprises was the ability to do a back kick to backup, they were very responsive.
The Video:
Landonnin1 was recording me when I was swimming out from shore and adjusting my camera, when I had no idea he was doing it. His thought was it was the best opportunity to capture my natural use of the fins. Some of the kicks were me feeling out the fins. They felt different and didn't appear to affect my buoyancy or trim. I'm uploading the videos to YouTube, when they are done, I will post the links here.
Weight and Bouyancy:
Because I'm carrying my large camera, a dive flag, and fins, I clip off the fins to my waist D-ring. Upon reaching standing depth, I removed my fins, clipped them together, and clipped them to my waist, or so I thought. I'm halfway to my truck and I realize I don't have the fins attached to me. 2 of the divers had already exited before me, but one was still geared up. We went back to the beach looking and looking. Do they float? The lifeguard said he saw some fins floating in the current, so Michael ran up the bridge to see if could see them. I snorkeled around and Matt went back underwater. There were so many people at the beach, did someone find them? I found Jenny taking pictures of something, so I swam to depth to get her looking around too. We looked for like 30 minutes and could not find them. Usually lost fins/masks are turned into a local LDS, so we gave up. We get back to the parking lot and one of our group members had found them and recognized them as the ones I was showing everyone. They said they were on the bottom, fins tips in the sand, foot pocket up in the water column.
Truefin is a little lighter than the Hollis F1. As I recall the weight of the large F1 was 3.8 pounds/fin, and Truefin is around 3.5/fin including spring straps. Regarding buoyancy, Truefin is around -3 ounces with spring straps, and I think the Hollis F1 was around -16 ounces, but I don't recall what the heel strap was with the Hollis F1 we weighed.
Regarding the flutter kick with Green spines, I guess it would depend on the individual, but the angle of attack during the 'toe down' power flutter kick between Green and Blue spines is the same, so you may find the Green spines flutter kick well. The difference would be how you want the fin to feel during the return flutter kick, and whether you want to be able to exert thrust during the return flutter kick. Green spines more readily produce thrust during the flutter return kick because the blade remains flat during the flutter return kick. However, typically during the flutter return kick most users may just want to relax the ankle a little to promote circulation and let the blade follow the streamline without attempting to exert thrust.