I was given a pair of F2s to test in late May, following RF3.0 in Orlando. That pair that I got were a pre-production display model and a little less stiff than normal.
During the next six weeks, I wore them cave diving -- pushing me in a drysuit, wearing a CCR and carrying two 12 litre bailout bottles against the flow in several north Florida caves including Jackson Blue Springs -- wreck diving in the Great Lakes -- again wearing a CCR and bailout -- and while I conducted several sidemount and CCR clinics in PA and OH, for a total of approximately 28 hours inwater overall. The tests were not exhaustive and I produced no data. Rather, in accordance to the usual "man" testing criterion, my conclusions are simply my impressions and opinions.
I have not spoken to Nick Hollis, about the target market, but I understand these have been designed in part as travel fins... something you can get into your baggage and fly with... and as scootering fins. They are light and a little shorter than most designs... certainly smaller than the Hollis Bat Fin (the F1). Each F2 has a mass of around 900 grams (less than 1lb 12 oz) including the spring heel strap. Packing a pair of these rather than my usual cave/tech fin would save me more than a kilo or a little more than a couple of pounds... not a lot but worth noting.
The lighter weight of course really does manifest itself in the water. As with most of the kit I take into the water, I put the F2s on a fish scale and weighed them in the water to find their adjusted weight... about 230 grams. It took me around five minutes to get used to having "nothing" on my feet, but I believe at the end of a couple of hours kicking, my legs appreciated the weight savings.
This time adjustment is key, IMHO. These are not like most of the fins I've used and it did take a while for me to get used to them. When I did, I liked them a lot.
I found the fit perfect. I wear a size 45 shoe... which is about a 12... and the fins I was given are X-large. They are comfy and I can back fin, frog-kick, flutter kick and do the can-can wearing them.
As with ALL the Hollis kit I have been asked to test or that I have purchased, the F2s are built like a brick ****-house. The materials and attention to detail is second to none... which in a fin is appreciated since I do not like swimming with one fin... although I have tried that with the F2s and they worked just fine.
Finish... someone mentioned their fins came with production marks on them.
I do not take very good care of fins... When I get back on the boat or surface from a cave, they are the first thing I toss into the corner... and when I pack my truck, the fins get jammed into the lockbox. Truth is, I cannot tell you how they looked when Dave Burroughs handed them to me and said: "give these a try." There may have been swirls and marks on 'em... I simply do not know. I can tell you that they look like a pair of dive fins now... I guess I could armor-all them but I really don't pay much attention to looks when a tool does the job it's supposed to. These do and in the areas that matter -- wear and stress points -- they look as strong as new.
The F2s are not going to win a beauty contest... although I think they look kind of cool... and they may not move a big diver through the water ultra-fast, but they are a great general purpose tech fin for someone looking for something that packs light and small, and perform as well as any of the alternatives. If you are going to swim five stage bottles and a video camera to the far end of the Prince of Wales, then invest in a pair of Hollis F1s however, if you are going to have to fly to Singapore to get on the boat to take you out to the Prince of Wales... or if you just want a compact functional fin... buy yourself a pair of F2s at a suggested retail less than $140, they strike me as a pretty damn solid investment.