I know this is going to be a sh.tfest.
Im personally a PB guy , only because my early boards and fins stock were.
Tuttle has 2 bolts , and when you hit something they only wedge in a bit front and back. A single bolt PB wedges front and back and sideways. Only happily needing one bolt.
Discuss 
ps , I regularly use a 55cm PB pointer and I'm heavy. Never had a problem .
Is Tuttle overkill ?
Tuttle= hit something hard , breaks box - you keep the fin and sail home.
Powerbox= hit same thing, breaks bolt, loose fin and you work out how to get home.
Its a New fin v new repair question.
BTW I only use Tuttles as I've had too many failures with PB
I find PB boxes seem to have a large manufacturing tolerance in dimension. So, fitting a PB fin to one brand of board, will either be loose at **** or won't fit in others. Tuttle boxes seem to have a much tighter manufactured tolerance.
On commercial boards the PB is a weak setup with a half height box and a single tube for the screw reaching up to the deck. It's essentially not much stronger than an US box.
Powerbox with something like a chinook box insert is very strong, however, as the box extends all the way up to the deck.
I prefer the fin to breakaway (ie. that's what a pb fin does) rather that the box ripping out of the board when I hit something (which is often).
Both should work if board and fin manufacturers could make them to tolerance. It's ridiculous how bad some boxes are.
Select to expand quotekato said..
Tuttle= hit something hard , breaks box - you keep the fin and sail home.
Powerbox= hit same thing, breaks bolt, loose fin and you work out how to get home.
Its a New fin v new repair question.
BTW I only use Tuttles as I've had too many failures with PB
Tuttle = hit something hard, breaks box - you keep the fin and sail home .
I wish. .
once all my boards were tuttle I decided that will be the choice for me... I have way to many fins and wouldn't want to double up needing a PB fins too.
I had to sail home without a fin a couple of times many years ago when the PB screw decided it was too fatigued to hang on to the fin without hitting anything. That's why I think Tuttle is better.
I guess it helps to stand back a bit.
All windsurf finboxes were developed as a reactionary response to breakage issues which emerged, as we tried to have longer fins which took sideways loads, with engineering issues which hadn't been understood before.
The longer the fin, the deeper rooted the head needs to be.
This is like planting a tree in a windy place or else concreting in a fence post - where the fence might blow down in strong wind.
Foil boards have similar (if not worse) issues, as people have tried to stick long foiling masts in shallow boxes originally designed for surfboard fins (like the shallow US box). Short surf fins do not exert leverage on the box, whereas longer slalom fins do.
So the Powerbox was a user-friendly adaption, using a deeper wedge connection idea, after all the shallow US boxes failed with longer fins.
The Tuttle was in turn a better solution for long fins, being deeper and having two bolts instead of one, plus a flat-sided fin head.
The Deep Tuttle is then the best, because it roots your fence post the furthest in the soil.
It's not really about what's best in a breakage situation.
He parallel sides of the Tuttle are really not a good idea for getting a good fit, what you really need is a power box head as deep as a deep Tuttle made to accurate tolerances
Select to expand quoteBen1973 said..
He parallel sides of the Tuttle are really not a good idea for getting a good fit, what you really need is a power box head as deep as a deep Tuttle made to accurate tolerances
I think so too.
Powerbox would be ok if it had two screws but with a single it really limits the fin length, even more so when using weed fins.
Still have memories of taking a brand new fin out on it's first time sail clipping a reef and leaving it there with nothing but a barrel nut left in the board.
I have clipped and hit a lot of things with a tuttle and never lost or had any damage from the impacts apart from myself with the rapid dismount.
Give me tuttle every time.
Select to expand quotesboardcrazy said..kato said..
Tuttle= hit something hard , breaks box - you keep the fin and sail home.
Powerbox= hit same thing, breaks bolt, loose fin and you work out how to get home.
Its a New fin v new repair question.
BTW I only use Tuttles as I've had too many failures with PB
Tuttle = hit something hard, breaks box - you keep the fin and sail home .
I wish. .
Buy a better quality board 
Select to expand quoteBasher
The Deep Tuttle is then the best, because it roots your fence post the furthest in the soil.
It's not really about what's best in a breakage situation.
Spoken like a true farmer basher , I understand rooting ;-),Tuttle and deep give a more firm powerful feel under foot
I use both as I have free ride boards
I have lost powerbox fins out to sea so they scare
me a bit , so I update the brass if I ever hit anything
I feel safer with two screws , but if you hit something hard you go over the front
I found out the hard way , I broke my neck in the process , I think I would prefer powerbox now , but I'll get over it and pay more attention next time ,
I may even just use a front bolt when sailing shallow , I have no problem with either boxes , both work , depends on your fin collection , I see a few of your fins filleted now IMAX so they will be pretty solid on the board ,i have mostly Slalom which mostly come in Tuttle .
Select to expand quoteBen1973 said..
He parallel sides of the Tuttle are really not a good idea for getting a good fit, what you really need is a power box head as deep as a deep Tuttle made to accurate tolerances
If the box and fin are made to accurate size, they both fit well.
I have all Tuttle as I ride Slalom and Speed boards, and those boards really only come with Tuttle boxes (My Wave boards have US box).
I have very rarely found fin head fit an issue, and if it ever was, it was very easy to fix. 
Powerboxes are only really applicable to freewave/freeride boards.
Select to expand quoteTardy said..Basher
The Deep Tuttle is then the best, because it roots your fence post the furthest in the soil.
It's not really about what's best in a breakage situation.
Spoken like a true farmer basher , I understand rooting ;-),Tuttle and deep give a more firm powerful feel under foot
I use both as I have free ride boards
I have lost powerbox fins out to sea so they scare
me a bit , so I update the brass if I ever hit anything
I feel safer with two screws , but if you hit something hard you go over the front
I found out the hard way , I broke my neck in the process , I think I would prefer powerbox now , but I'll get over it and pay more attention next time ,
I may even just use a front bolt when sailing shallow , I have no problem with either boxes , both work , depends on your fin collection , I see a few of your fins filleted now IMAX so they will be pretty solid on the board ,i have mostly Slalom which mostly come in Tuttle .
Nylon bolts may help 
good thinking . what do I look for M6
if the fin breaks off in our reef I usually can find it .
I went out the other day but I was like a cat walking around a swimming pool .
what about alloy ,? would that be slightly stronger and still strip .? or maybe look at brass bolts .hhmm .great safety thinking choco .
Select to expand quoteTardy
I have lost powerbox fins out to sea so they scare me.
I see a few of your fins filleted now IMAX so they will be pretty solid on the board ,i have mostly Slalom which mostly come in Tuttle .
Yeah , but I still use 55 cm pointers and have never lost one. I do re nut to the larger 12 mm nut if they come with the smaller 9 mm nuts. The filleting concept is awesome , thanks Fangy.
Select to expand quoteImax1 said..Tardy
I have lost powerbox fins out to sea so they scare me.
I see a few of your fins filleted now IMAX so they will be pretty solid on the board ,i have mostly Slalom which mostly come in Tuttle .
Yeah , but I still use 55 cm pointers and have never lost one. I do re nut to the larger 12 mm nut if they come with the smaller 9 mm nuts. The filleting concept is awesome , thanks Fangy.
I would always go for big nuts
Select to expand quote
Nylon bolts may help
I'm sorry to say , but those nylon bolts would be horribly under strong enough .
I think if you want to go down that road , drill a 5.3 / 5.4mm hole down the thread . If it's a older fin it probably has worn down to that size anyway .
either that or cut the bolts shorter so only half goes in ,i think its 4 turns ,theres a puzzle for you IMAX . ,
i hit at 50-55 klms they never gave way .
Select to expand quoteTardy said..
either that or cut the bolts shorter so only half goes in ,i think its 4 turns ,theres a puzzle for you IMAX . ,
i hit a 50 klms they never gave way .
Nooooo. You want the bolt to go all the way through and then some . That way you have half a chance that it still hangs on after stripping the nut , after the fin kicking back.
Ok I was more referring to tuttle box ,my powerbox fins always strip when hit .
I Think i will run one stainless and one nylon ,till my nuts grow back .
Select to expand quoteTardy said..
Ok I was more referring to tuttle box ,my powerbox fins always strip when hit .
I Think i will run one stainless and one nylon ,till my nuts grow back .
Just don't swing off the screwdriver , that plastic bolt will strip just looking at it. I'm not sure if it will be strong enough to level the fin in the box. Unless you pull the fin down with 2 stainless bolts , then replace the back one with plastic . Still I cringe.
Select to expand quotesailquik said..Ben1973 said..
He parallel sides of the Tuttle are really not a good idea for getting a good fit, what you really need is a power box head as deep as a deep Tuttle made to accurate tolerances
If the box and fin are made to accurate size, they both fit well.
I have all Tuttle as I ride Slalom and Speed boards, and those boards really only come with Tuttle boxes (My Wave boards have US box).
I have very rarely found fin head fit an issue, and if it ever was, it was very easy to fix.
Powerboxes are only really applicable to freewave/freeride boards.
With parallel side the fin has to be a loose fit or you would never get it in without a press, yes it's probably tight enough but tapered would make it much better, wouldn't need much of a taper.
the only board and fin combo I've had that actually fit was in a Fox with the factory fin, shame thay forgot to glue the box into the board
Team Imax!~ Yep for me, it's power box, but with some specific caveats. The fins I use are all relatively short, so the lateral leverage is lessened. The fins all have a fillet to distribute lateral loads on to the top of the box as well as the walls. These two factors nullify the lateral loading benefit of tuttle box design. I use 12 mm diameter brass barrel nuts and good quality stainless steel bolts that are full depth and engage all 12 mm's of the nut. I use hex heads and do them up real tight. With those precautions in place, I think the power box is a more elegant solution and a better resolved design. It is lighter, easier to align and seat a fillet based fin correctly. But I stress this only applies to my circumstance, and I totally understand the longer non fillet fins benefiting from the tuttle concept and the safety net of breaking stuff out at sea. On that note, when you snap/lose a fin, I have found tying my camelpak to the rear foot strap and trailing it in the water works well enough to sail back to shore. Note, you do have to keep the speed down in order to keep the camelpak in the water and providing enough drag.
Three boards, three different fin boxes. All are fine. Would be happy if all were identical. Actually would be happier if the windsurfing industry would adopt a single standard fin box. Deep Tuttle would probably be the more versatile. Allow use of foil mast, std tuttle and deep tuttle fins. Maybe too deep a box for lower volume wave boards? Hard to see a DT fitting on my ancient 86L wave board.
On Maui I just nicked a reef. Standard American slot tab fin. Lost the fin. But I was happy that I didn't hit reef and the tail of the board was not damaged. Did the same thing with a power box fin. Unlike me who took a flyer, the fin stayed attach to the board. Chipped off the tip. Few seasons ago. Box still seem solid.
Select to expand quoteBasher said..
I guess it helps to stand back a bit.
All windsurf finboxes were developed as a reactionary response to breakage issues which emerged, as we tried to have longer fins which took sideways loads, with engineering issues which hadn't been understood before.
The longer the fin, the deeper rooted the head needs to be.
This is like planting a tree in a windy place or else concreting in a fence post - where the fence might blow down in strong wind.
Foil boards have similar (if not worse) issues, as people have tried to stick long foiling masts in shallow boxes originally designed for surfboard fins (like the shallow US box). Short surf fins do not exert leverage on the box, whereas longer slalom fins do.
So the Powerbox was a user-friendly adaption, using a deeper wedge connection idea, after all the shallow US boxes failed with longer fins.
The Tuttle was in turn a better solution for long fins, being deeper and having two bolts instead of one, plus a flat-sided fin head.
The Deep Tuttle is then the best, because it roots your fence post the furthest in the soil.
It's not really about what's best in a breakage situation.
Good summary Basher.
I thought the Tuttle came before the Powerbox. I remember getting my first Tuttle box board in 1989 or 1990 . But didn't see the Powerbox till Mistral and F2 (Sputnik etc.) starting using them in the early 90s. I always assumed it was a patent standoff. I do remember many of the early adopters of the Powerbox losing fins repeatedly due to the bolts failing. This was enough to convince me to steer clear of the Power box.
