JS Blak Box 2 Round Tail 6'3 (2015) review: under volume with a blown fin

Updated 2026-09-19

This earlier JS Blak Box 2 Round Tail, also 6'3, came before the 2016 version in the log and ran into its own specific issue: it sat under volume for its rider, and at one point blew a fin out entirely.

What it is and why I bought it

I bought this Blak Box 2 stock in July 2015, a board with a fat rocker and hard rails, running a single-to-double-concave bottom, finished with a rounded pin tail and five fin slots, the same model family as the later 2016 version. At 21 inches wide and 36.5 litres, it carries a touch less volume than its later sibling.

How it surfed

Its best wave came at Cokes, and it put in solid work despite running under volume for its rider, a mismatch the register notes directly. At one point it also blew a fin out, a mechanical failure worth knowing can happen even on a well-regarded model. The logged wave range is 2 to 5 ft, ideal at 3 ft.

Who it suits and who it does not

A five-slot hybrid like this suits a lighter rider who can work with slightly less volume than average for the length. It is a weaker fit for a heavier rider, exactly the mismatch logged against this particular board, and it is a reminder to check fin box condition carefully on a secondhand five-slot board.

What happened to it

It sold on 15 May 2016 for $400, against an $850 purchase cost.

Questions people ask

What went wrong with this board's fin setup?

It blew a fin out at one point during its time in the rack, a mechanical failure worth checking for on any secondhand board with a similar five-slot setup.

How does this compare to the later, 2016 version of the same model?

Both share the same 6'3 five-slot Blak Box 2 design; this earlier one ran slightly less volume at 36.5 litres against 37.5, a small but real difference for a rider close to the board's limit.

What conditions suited this board?

The logged range is 2 to 5 ft with 3 ft as the ideal.

For the full spec sheet, see the sold boards list. For the later version of this board, see the 2016 JS Blak Box 2. For what to check when buying a used board, see buying a used surfboard.