Foil Strongbox


This install is available at H/C Surf & Paddleboards. Please contact us for a price quote.

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.
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 patent pending design, all rights reserved, copyright Blue Planet Surf Gear, 2019
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.

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