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Foil Strongbox

Foil Strongbox
Foil Strongbox
Foil Strongbox
Foil Strongbox
Foil Strongbox
Foil Strongbox
$179.00 Excl. tax

Blue Planet's Patented Foil Strongbox design Read more..

The Blue Planet Foil Strongbox is a patent pending design to optimize the performance compatibility of your foil SUP or surfboard.

They are made from carbon fiber, high density foam and tuttle/center fin boxes and will be compatible with both the deep tuttle and plate mounting options. By combining both mounting options into one box, the Foil Strongbox makes your board compatible with most foils on the market. 

All Blue Planet SUPs and prone foil boards feature our patent pending Foil Strongbox. 

If we are sold out, the Foil Strongbox is also available on Amazon:

It is also available internationally on Amazon in Canada, Australia, and UK

Watch the video for details and installation instructions:

Dimensions (approx): 11.2" x 5.5" x 5.13" (maximum board thickness at foil placement is 5.13” without modification)

Weight (approx): 34 oz

Installation Steps:

1) measure location, mark top/ bottom- see below for recommended measurements

2) drill pilot holes from top and bottom, cut out with long blade

3) measure and cut Foil Strongbox to fit thickness of board

4) remove deck pad around box, tape off deck opening and cover with plastic covered wood piece

5) apply gorilla glue to box and board, wet with water mist

6) adjust box to be flush, plum and square before glue sets

7) trim excess glue, prep for glassing

8) glass with 3 layers carbon, plus one layer 4 oz glass to prevent seepage on bottom, cover with plastic

9) sand, hotcoat

10) cut out box openings with pilot holes, trim router

11) drill Tuttle holes with long drill bit

12) put washers over holes on deck, cover with deck pad Here is a link to the trim router bit that Jeff uses:

We welcome inquiries from board builders, trade pricing available for bulk orders. Foil Strongbox™ is a patented design (US patent #10773775)

Recommended box measurements from tail of board to back of Tuttle opening (as per

Board Length Distance from tail of board
3′ to 4’6″” 1′ to 6″
4’6” to 4’11” 4” to 8”
5’0″ to 5’9 6” to 12”
5’10” to 6’6” 8” to 15”
6’7” to 7’4” 12” to 20”
7’5” to 8’6” 16” to 22”
8’7” to 9’6” 20” to 28”

Prone surfboards in general need the box further back than a SUP. This is because the lighter the board, the less lift you need to make and/or keep it foiling.

Think of your back foot on a prone board where you would like to place it when standing up into surf position. Generally, your foot will be close to standing directly on top of the mast when on a prone board or slightly forward of that position.

On a SUP, you can stand slightly aft of the prone position, so many stand on the trailing edge of the mast on their SUPs.

Box placement further forward creates greater lift and earlier planing but you will be standing further towards the nose to balance it.

Box further back usually helps the boards turn ability.

Lightweight riders need less lift and heavy riders need more lift so consider the riders size when choosing box placement.

Please note: the Foil Strongbox is designed for foils with square/ straight deep Tuttle heads as found on GoFoil, Blue Planet, and many other Surf Foils on the market (see image on the right below).  If your foil has an angled foil head and the screws come out at an angle (like the two images on the left), the screws will not line up with the holes on the deck.  It is possible to use an angled tuttle head in the Foil Strongbox by elongating the screw holes on the Tuttle head so the screws can come out of the head parallel to the mast, see image below of a Tuttle foil head with elongated holes that is compatible with both square and angled mounting boxes. 

Also note that the head is locked tight into place by getting tightened between the angled front and back of the opening, not by touching the bottom of the box.  There is usually a small gap between the tuttle head and the bottom of the box, this is intentional and not a cause for concern.


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