Will Bosi


Quick Info

From: United Kingdom 🇬🇧
Date of birth: 27th December 1998
Age: 27 years old
Gender: Male
Hardest Boulder (Worked): 9A
Hardest Boulder (Flash): 8B+
Hardest Sport (Worked): 9b+
Hardest Sport (Onsight): 8b
Hardest Sport (Flash): 8b+
Notable Partnerships
Aidan Roberts

Will Bosi is a climber from Edinburgh in Scotland. He started out as a competition climber, first progressing through national competitions and then European youth comps where he had a string of podium finishes. He struggled somewhat to replicate the successes of the youth comps in the adult circuit, with his best performances being two 4th place finishes in 2019.

Since retiring from comps he has turned to sport climbing and bouldering outdoors, where he has been extremely successful. In 2020 he became the second British climber to climb 9b sport with his repeat of La Capella. He then replicated this success in 2021 with hard first ascents and repeats including among others:

Since 2022 he has focused more on bouldering, where he has also excelled. For example he flashed Charizard 8B+ and, as of 2024, has climbed five 9A boulders:

References

[1] My Climbing Journey April 2023, https://www.youtube.com/watch?v=ZmmMbpCsSuA

[2] https://www.youtube.com/watch?v=Cn1dJNPfAfc

[3] https://www.climbing.com/people/interview-will-bosi-spots-of-time/

Contributors
715 contributions since 6th May 2021.
43 contributions since 2nd January 2025.
8 contributions since 21st February 2024.
ben
7 contributions since 15th December 2025.
2 contributions since 21st October 2025.
2 contributions since 3rd December 2024.
2 contributions since 21st February 2024.
TdG
2 contributions since 11th August 2025.

Quick Info

From: United Kingdom 🇬🇧
Date of birth: 27th December 1998
Age: 27 years old
Gender: Male
Hardest Boulder (Worked): 9A
Hardest Boulder (Flash): 8B+
Hardest Sport (Worked): 9b+
Hardest Sport (Onsight): 8b
Hardest Sport (Flash): 8b+
Notable Partnerships
Aidan Roberts

Will Bosi is a climber from Edinburgh in Scotland. He started out as a competition climber, first progressing through national competitions and then European youth comps where he had a string of podium finishes. He struggled somewhat to replicate the successes of the youth comps in the adult circuit, with his best performances being two 4th place finishes in 2019.

Since retiring from comps he has turned to sport climbing and bouldering outdoors, where he has been extremely successful. In 2020 he became the second British climber to climb 9b sport with his repeat of La Capella. He then replicated this success in 2021 with hard first ascents and repeats including among others:

Since 2022 he has focused more on bouldering, where he has also excelled. For example he flashed Charizard 8B+ and, as of 2024, has climbed five 9A boulders:

References

[1] My Climbing Journey April 2023, https://www.youtube.com/watch?v=ZmmMbpCsSuA

[2] https://www.youtube.com/watch?v=Cn1dJNPfAfc

[3] https://www.climbing.com/people/interview-will-bosi-spots-of-time/

Contributors
715 contributions since 6th May 2021.
43 contributions since 2nd January 2025.
8 contributions since 21st February 2024.
ben
7 contributions since 15th December 2025.
2 contributions since 21st October 2025.
2 contributions since 3rd December 2024.
2 contributions since 21st February 2024.
TdG
2 contributions since 11th August 2025.

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Ascents

148 recorded ascents.

This timeline is missing some ascents where the date of the ascent is unknown.
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Climb Grade Style Ascent Date Suggested Grade

References

[1] https://www.youtube.com/watch?v=BNAfAujGczo

[2] Footage from Will's first trip in 2025 https://www.youtube.com/watch?v=ujb7YRfE-7k

Exactly 2 years after Stefano Ghisolfi made the first ascent!

The first go of the day everything went perfectly, I felt like I was floating through climb and arrived at my previous high point feeling strong. Setting up for the final hard move I was really confident but disaster struck and I just missed the hold and fell of I took an hour rest, warmed up and went again. This time I arrived at the rest feeling tired battling through the upper section but on the final crux I landed perfectly into the slot. Pumped out of my mind, I almost fell jumping to the jug but just about kept it together for the top out.

References

[1] https://www.instagram.com/p/DFsLqiGC1tc/

[2] https://www.ukclimbing.com/news/2025/02/will_bosi_makes_the_second_ascent_of_excalibur_9b+-73894

[3] https://open.spotify.com/episode/1RjDH1oAZkr9epcy4LrA0l?

[4] https://www.youtube.com/watch?v=hZS2IWZLmqg

Second ascent of a 9b by a brit, and the first british repeat of an established 9b.

The long awaited second ascent after 4 years and 40 sessions.

Finally! This was by far and away my longest project on a route and I am so happy to clip the chains. It is so typical of the redpointing game that the route went down on the last go of the day with little expectation that I would send it! Full credit to Steve McClure on an amazing first ascent and for establishing a climb with such amazing moves. [1]

References

[1] https://www.ukclimbing.com/news/2021/11/first_repeat_of_mutation_9a_by_will_bosi_proposes_9a+-72918

[2] https://www.instagram.com/p/CVxr19WLZRL/

[3] https://www.instagram.com/p/CVxrF8ZoBB8/

[4] https://www.youtube.com/watch?v=MBDqpUKgAyE

The climb is very similar to Hubble in a sense but the sequence of moves are a lot more complex and technically demanding. I was stuck for a while on the lower section but once I was able to unlock a sequence, the route came together really quickly for me. [2]

References

[1] https://www.youtube.com/watch?v=CqoVQxpYwlw

[2] https://www.ukclimbing.com/news/2021/11/first_ascent_of_brandenburg_gate_project_by_will_bosi_proposes_9a+-72925

[3] https://www.instagram.com/p/CWAkBKEouWd/

Although there seems to be a lot of holds from the floor, almost everything is an undercut or a side pull. This makes the climbing very technical as the feet are tiny! The climbing is also very intense and powerful as you cannot relax. [2]

References

[1] https://www.instagram.com/p/CflFrCfIxHK/

[2] https://www.ukclimbing.com/news/2022/07/first_ascent_of_scotlands_hardest_route_by_will_bosi_-_free_at_last_9a+-73090

Rainshadow 9a Lead | worked 2nd May 2016
Hunger 9a Lead | worked 3rd Apr 2018
Estado CrĂ­tico 9a Lead | worked 24th Feb 2021
Roofolution 9a Lead | worked Mar 2022
Stevolution 9a Lead | worked 17th Mar 2022
Evolution Third go. 8c+ Lead | worked 4th Jul 2017
Progress 8c+ Lead | worked 17th May 2025 8c+ (soft)
Malcolm In The Middle Second ascent? 8c+ Lead | worked 31st May 2025
Make it Funky 1 session. 8c Lead | worked 30th Nov 2017

Another crazy hard 8 grade route at the tor, maybe a hold broke?? [1]

References

[1] https://www.8a.nu/crags/sportclimbing/united-kingdom/peak-district/sectors/raven-tor/routes/seraphim

[2] https://youtu.be/CJYfOrjj0uo?t=220

El MĂłn de SofĂ­a 8b+ Lead | flash 11th Apr 2017
Climb Grade Style Ascent Date Suggested Grade

Before the first ascent Will had been playing on the boulder with Dave Graham and trying some of the moves. At the time the line seemed too futuristic so he didn't dedicate to it.

After Shawn Raboutou made the first ascent Will got psyched on the line again and headed out with Aidan Roberts, initially just to try the line and then, when he made quick progress, to send it.

In terms of a grade, I personally felt that Honey Badger was more of a challenge for me and proposing a grade for that at the time was daunting as it was my first 8C+. At the cutting edge of climbing, grading feels so much more difficult as the margins are that much finer and personal strengths and preferences really come into play.

Is it 9A? Honestly, I do not know and as I gain more experience of climbing around this grade range I may have a better view, but it is a fantastic line established by Shawn [Raboutou] and I look forward to seeing more experienced climbers comment on where the grade sits. [2]

References

[1] https://www.instagram.com/p/CkdgyVDDNAZ/

[2] https://www.ukclimbing.com/news/2022/11/will_bosi_claims_the_third_ascent_of_alphane-73186

[3] https://www.youtube.com/watch?v=8uBS9OYa2P8

[4] https://www.youtube.com/watch?v=DEUdY5otiqM

12 sessions in total, including 3 spent on the stand start Sleepwalker, completed during a single trip to try the boulder.

In the last session before the send, everything just clicked. I was feeling confident, but as the weather forecast looked bleak with a storm closing in, I was only able to take one rest day before heading back out for another session. I still felt quite tired from the previous session so I was unsure about even trying it.

However, after warming up, the moves were feeling great and I decided to give it a go. The first attempt went perfectly up to the sloper but then I really messed up the next move through to the slot and almost dropped it. Somehow, I recovered and hit the last hard move perfectly. Pulling onto the slab was incredible and I had to take a minute to get my breath back before heading up to the top. [1]

References

[1] https://www.ukclimbing.com/news/2024/02/return_of_the_sleepwalker_9a_for_will_bosi-73602

[2] https://www.instagram.com/p/C3nLKdJrZCC/?img_index=1

[3] https://open.spotify.com/episode/3PwOTtkyJJ3IM0A8MxUemD?

[4] https://www.youtube.com/watch?v=8awesjyAGTg

Matt Bird: So Will, what grade is it then?

WB: I have been thinking so much about the grade ever since I started work on the project. I find it so hard to grade short, powerful boulders as so much of the grade weighs on fewer individual moves and the grade can shift dramatically around based on small changes in beta and whatever style suits the climber.

However, providing a grade based on my own experience of other hard boulders as well as boulders on Raven Tor and Peak Lime, I am pretty confident in suggesting that this sits as a low-end 9A boulder.

MB: Ok, let’s break it down then - why is it not 8C+?

On Raven Tor itself, to the left of Realm, are two boulders which are essentially one-move 8A+’s. The crux move on Realm is at least one to two grades harder and is comparable to the first move on Burden of Dreams. Stitching the crux move and the last move took so many sessions. Even matching the final hold is a real effort!

Looking at other hard single-move boulders I have done elsewhere, the crux move is significantly harder than other lines such as Forgotten Gem (8C/V15, Chironico, Switzerland) and Silent Singer (Bowderstone, Lake District, 8C/V15).

Comparing the whole boulder to other short, powerful 8C+ boulders, it feels harder than Brain Rot (8C+/V16 Magic Wood) and Ephyra (8C+/V16 Brione).

It is incomparable to 8C+ like Honey Badger (Badger Cove established by Bosi in 2022) as it is 20 minutes down the road but feels like a totally different boulder problem. Honey Badger has way more moves making it difficult to compare with Realm as they were different styles. However, I put in way more time on this boulder than I did on Honey Badger, which consciously or subconsciously made me think this was a harder overall problem.

MB: So, how does it compare to 9A’s you have done?

Straight away, we can discount Return of the Sleepwalker and Alphane as comparisons because they are such different boulders in terms of style compared to Realm.

So the comparisons from my own experience come to Burden of Dreams and Spots of Time. I think Spots is the best comparator as it is in the UK. I did it recently [Winter 2024], and it is a short boulder similar to Realm.

For me, the crux of Realm is slightly harder than the crux of Spots simply because the key hold is flat, slippy limestone, but when you put all of the moves of each boulder together, they come out around the same grade. I do think Spots and Realm are a step above the 8C+ boulders I have done to date, so that is why I am proposing a low-end 9A boulder grade. As always, I am excited to hear what others think as they try the problem as it is at Raven Tor, so I am hoping it will get a lot of attention! [1]

References

[1] Press release /file/e85dc179-1c14-6a29-c466-81f955348780/PRESS RELEASE_BOSI_9A FIRST ASCENT_PEAK DISTRICT.pdf

[2] https://www.instagram.com/p/DJ4S7KMoLpV/

[3] https://www.ukclimbing.com/news/2025/05/will_bosi_establishes_realm_of_torment_9a-73972

[4] https://youtu.be/bb4PMysTmyM?

In terms of a grade, I personally felt that Honey Badger (8C+) was more of a challenge for me and proposing a grade for that at the time was daunting as it was my first 8C+. At the cutting edge of climbing, grading feels so much more difficult as the margins are that much finer and personal strengths and preferences really come into play. [3]

References

[1] https://www.youtube.com/watch?v=wtSeQ8Xm3mw

[2] https://www.patreon.com/posts/mastery-extras-80893007

[3] https://www.ukclimbing.com/news/2022/11/will_bosi_claims_the_third_ascent_of_alphane-73186

I did one at Raven Tor, Wild South, which I tried a crazy amount of days, but I was ignoring a kneebar for a long time because I didn’t want there to be a kneebar there. Then one day, I tried a kneepad, and it worked really well. I gave that climb 8C because when I started trying the knee, it only took two sessions, and it didn’t feel as bad, but looking back I’m thinking it didn’t feel so bad because I’d spent so much time on the rest of the boulder. So I think that’s probably an 8C+. [2]

References

[1] https://www.youtube.com/watch?v=zf16iiXqOT8

[2] https://www.climbing.com/people/interview-will-bosi-spots-of-time/

Will used different beta to Aidan (keeping the right heel in to match the left hand in) which he felt was more 8C than the 8C+ that Aidan proposed.

References

[1] https://www.youtube.com/watch?v=pcB7xINW-ek

Will was close to climbing the problem on his second session, dropping it with his right hand in the slot and left hand on the sloper. He then did it on the first go of his third session.

References

[1] https://www.instagram.com/p/C2Xf6BpreZ5/?img_index=1

[2] https://www.youtube.com/watch?v=Z44acjCBPMA

Foundation's Edge 1 session. 8C Boulder | worked 23rd Sep 2021 8C
Ghost Rider 8C Boulder | worked 9th Apr 2022

Will was close on the flash, slipping off after the crux! He finished the problem off on his fourth try.

References

[1] https://youtu.be/dP5AD_M2dE4?t=236

Super happy to send this! Now onto the full line of Terranova :) Grade wise it felt like the hardest or joint hardest boulder ive done in the Czech so i think it deserves the C but time will tell

References

[1] https://www.instagram.com/p/CzWTqA3NED0/?img_index=1

[2] https://www.youtube.com/watch?v=IIxlU0Boplc

Dandelion Mind 8B+ Boulder | worked 17th Jul 2020 8B+
Bhai Po 8B+ Boulder | worked 1st Mar 2021
Scarred For Life 8B+ Boulder | worked 11th Oct 2021

Desperate!!! was a proper battle reckon it could be 8B+ now

References

[1] https://youtu.be/Y7AoI8zN6cA?t=436

Prehistorik 8B+ Boulder | worked 28th Apr 2022

Will broke a foothold on his first go which made the sit unfeasible. However he then did the problem from a crouch start and suggested 8B+ for this.

References

[1] https://www.instagram.com/p/CiFZugbjmly/

Will used some different beta which he found a little easier than the original sequence.

References

[1] https://www.instagram.com/p/Chr-yz5jPdn/

First go after warming up on the moves.

Dente de TubarĂŁo Low First ascent. 8B+ Boulder | worked Sep 2024
Gaston LeGume 1 session. 8B+ Boulder | worked Sep 2024

Some of the holds have broken/deteriorated since Jana Švecová made the first ascent which is why Will suggested an upgrade.

References

[1] https://www.youtube.com/watch?v=FjMyQjd4lig

Mortal Immortal 8B+ Boulder | worked 13th May 2025 8B+ (soft)
Milk It
Indoor
8B Boulder | worked 2021
Perky Pinky
Indoor
8B Boulder | worked 2021 8A+

Will was the first to repeat it post break and suggested the boulder was more on the 8B+ side now.

Yeah, it’s such a good problem! Learning the move took a while, but in the end, I didn’t quite hit the right hand. Still, I felt solid in the position and was able to sketch through to the top. Instead of using four fingers, I had to go with three, and when I hit that crimp, I fully crimped on it. At that point, I was just praying it wouldn’t rip and hoping for the best up there. I think it’s been three years since the hold broke, and I don’t think anyone has done that move until today. It’s a hard one—people have tried it, and from those I’ve spoken to who attempted it before and after the break, they say it’s a lot harder now. I never tried it before, so I can’t compare, but it definitely felt hard for the grade. With grit, when you finally send the climb, the sequence always seems to work out better and feels a bit easier. But to be honest, this one still felt pretty tough at the top. There aren’t many moves, and I suppose with a lot of good days and good skin, you could learn it quite well. Still, it felt hard. I was pulling really hard through the top. I definitely think it’s more than likely on the 8B+ side.

References

[1] https://www.instagram.com/p/CZCx-QfINLd/

[2] https://www.youtube.com/watch?v=1xgXpMRj1HY

Third go after getting tantalisingly close on the flash.

References

[1] https://www.instagram.com/p/Caz4gd1N67f/

[2] https://www.youtube.com/watch?v=WUXlT20BcMo

Leda Kost 8B Boulder | worked 25th Mar 2022
Somnolence 8B Boulder | worked 1st Feb 2023 8B (hard)
Godzilla SDS 8B Boulder | flash Jun 2023
Needle and Rabbit First ascent. 8B Boulder | worked 24th Aug 2024
Dente de TubarĂŁo First ascent. 8B Boulder | worked Sep 2024
Dulcifer 8A+ Boulder | worked 3rd Oct 2021
Keen Roof 8A+ Boulder | worked 19th Nov 2021
Lethal Design 8A+ Boulder | flash 10th Mar 2024
Xuta Cavalo 8A+ Boulder | flash Sep 2024 8A (hard)
Cavaleiro Negro 8A+ Boulder | flash Sep 2024
El Dorado First ascent. 8A+ Boulder | worked 4th Mar 2025
Sundial Second ascent. 8A Boulder | worked Before 12th Apr 2025
Climb Grade Style Ascent Date Suggested Grade

Will dropped the crux on first go then fired it off next effort. His first trad fall!

Climb Grade Style Ascent Date Suggested Grade
Milk It 8B Boulder | worked 2021
Perky Pinky 8B Boulder | worked 2021 8A+