Go Foil users... how about one of these?

sure no reason at all. just remember to put plenty of carbon on it as this is where 100% of the load is. if you make it just like a short mast with the tuttle box in the bottom then you will hardly notice the extra drag

i'd say ali would just bend, there wouldn't be a lot of meat around the corners of the box where all the stress is. no reason a carbon one wouldn't work and you're probably dead right, why sell a $200 adapter when you can sell a $1200 mast.

Before even getting into making an extension or buying a longer mast. Have you been foiling long enough to understand how to react to the dips & troughs on the water surface. Is your technique right so that you don't breach? Is your foil wing too big? Is your foil set too far forward? Is the water depth too shallow.
In my experience being 80kgs in weight I feel much more comfortable using a medium sized wing, (NeilPryde) in shoulder to overhead waves than using a large foil wing on my SUP. But even then I have to react to the dips & troughs of the water surface that's caused from wind chop & side swells. Same as when riding a bike on trails with a law inside your head saying keep both wheels on ground when riding into dips & troughs otherwise your disqualified!
So if your front wheel goes up then you're out! Same with foiling. If you see a trough in front, go down into it & not straight ahead or up. That's when you breach & go over & nose dive. Reading the surface gives the best advantage & becomes automatic over time.
I too want a longer mast at about 75cm or 29.5 inches for my medium wing foil on those head high heavy waves with chop & side swells. And probably will need one in future when using a wingding. Not easy saving dollars without a job.
An extension between the mast and board will definitely have to be made strong. That is the area one of my masts have bent a few times in side on wave hits.
If one can be made at the fuselarge then I believe there would be less stress acting against it. But how do you make one there that will be streamlined enough?

If you are using the tuttle, they do have an adapter as DWF says...buddy has one, extends it about 4". Or if you are using the base plate adapter, that already adds 3", effectively a 27".

I am using the base plate adapter on surf foil and then the 24" tuttle on sup foil, both work fine in surf, very rarely breach. Though for winging, in high winds with large wind chop, I find need to slow down a lot to avoid breaching through the wind waves. So the longer mast would be helpful there.

I agree with SeaJuice ... If you are breaching a lot, then you are likely over-winged. My rule is that the Maliko 200 is for waist high waves maximum, any bigger than that, you should be on a smaller wing. And you will be stoked when you do ... suddenly those drops that you are on tiptoes just barely hanging on, you can drive through hard with confidence. You can also go way faster and do sharper turns. [keeping in mind GF doesn't even market these Malikos for surf, they are made for downwinding, using them in surf actually voids the warranty...which I find quite bizarre, as they are excellent in small surf]

With everyone going to the GL high aspect series, there are "cheap" older style wings for sale ... watch the Hawaii craigslist for the best deals, shipping is expensive, but a lot cheaper than buying new! You can also probably get an entire combo with the 29" mast and multiple wings for $1000ish US....and then you have all the smaller wings too and a spare mast. Awesome to have surf foil and sup foil both set up on the beach and switch off! More gear is good. :-)

Yeah try the IWA. I think it's close in size to the NP large. For your weight I think you'll have better control in surf. But I think an extension with your 200 would be better for the wind wing.
And agree entirely that prices are far too high for foils & their parts! I just laugh at the price of simple stainless bolts That you can get for much cheaper elsewhere.
Another thing I thought of a while ago was to get a 100mm/5inch thick plate between the original mast adapter plate & the board with the front of it V shaped to make it a little streamlined But! You will need longer track box bolts. And not sure what extra stresses it will make on the track box.
Just wondering if anyone has tried similar?
Sometimes I wonder if riders are getting too used to flying high and get disappointed when breaching when water surface changes.
But it would definitey be an advantage for wind wings, side swells & large chop. Plus high performance surfing.
But for shallower water & reefs 50 or 60cm masts are great.

If your 90kg and riding a M200 in large surf i get why your breaching. The M200 has a ton of initial lift. your better off putting your money into a Gl210 or 180, less initial lift and will hold a ton more speed.

This is what you seek. It adds 3" to the tuttle mast. A buddy got it as part of the package when he bought a used GF setup from Maui ... but in a google search, I haven't found a source yet.