A sluice box is the oldest trick in gold prospecting that still works. Point a stream of water down a sloped channel, feed gravel in at the top, and let gravity and moving water do what your pan does in miniature — except a sluice processes gravel by the shovelful instead of the handful.
It’s also the piece of gear most beginners get wrong first, because almost everything written about sluice boxes is written for wide, slow American rivers. New Zealand’s gold-bearing rivers — the West Coast, Otago, Nelson-Marlborough — tend to run faster and shallower over shorter stretches. A box sized for a lazy Californian river can be wrong for a Buller tributary in ways that cost you gold before you notice.
What actually matters when you’re choosing one
Width and length first, water flow second. A 12-inch mini sluice is built for sampling — testing a new spot before you commit gear to it — and for light, one-person recovery in tight creeks. Once you’re processing real volume on a day trip, boxes in the 27–34 inch range are the working size most prospectors settle on. Anything longer than that (up to the 50-inch folding boxes) is for someone running serious volume, not a first purchase.
The trap: a wider box needs more water moving through it to work the riffles properly. Heavy expanded-metal riffles want a strong, consistent flow across the full width of the box — undersized flow and the gravel just sits there instead of sorting. If the stream you’re actually going to use it in runs thin in summer, a narrower box that flow can properly drive will out-recover a wider one it can’t.
Riffles and matting — what’s actually trapping the gold. Almost every sluice box uses two or three trapping stages, not one. First stage is usually a carpet, ribbed matting, or “miner’s moss” — this is what catches the finest gold before it has a chance to wash further down. Second stage sits over or after that: either expanded metal, or a proper riffle system (the ridged bars you can see across the box). Some boxes stack all three — matting, expanded metal, then riffles on top — for maximum hold. More stages generally means better fine-gold recovery, but also more setup and more material to clean out at the end of a session.
Classify to your riffle size. This is the detail beginners skip and pay for later: whatever mesh size your classifier screen is (the sieve you run material through before it hits the sluice) should roughly match your riffle spacing. Feeding oversized rock into fine riffles just clogs them; running everything through a mesh too fine for your riffles wastes time screening material the box could have handled anyway.
Picking a size for your situation
- Sampling a new spot, or working alone in a tight creek: 12-inch mini. Light enough to carry in, cheap enough that a wrong guess doesn’t sting.
- A regular day-trip setup on a river with decent flow: 27–34 inch. This is the size most NZ weekend prospectors actually run.
- Backpacking into harder-to-reach ground (the kind of spot a lot of NZ’s public fossicking areas actually are): weight matters more than width — look for the lighter aluminium builds in the smaller size range rather than defaulting to “bigger is better.”
- Running real volume, or working a claim seriously: 50-inch folding boxes, but this is a second-purchase size once you know your ground, not a starting point.
Buying it
Mine For Gold doesn’t currently hold sluice box stock — worth saying plainly rather than pointing you at something out of stock. What matters more than which retailer you buy from is matching the box to the criteria above: size to your river and how you’ll carry it, riffle stage count to how much fine gold recovery matters to you, classifier mesh to your riffle spacing.
If you’re still working out where you’re legally allowed to run one, start with prospecting for gold and panning for gold — sluicing sits one step up from panning, same legal ground rules apply.
Looking at a secondhand box instead? Our guide to buying a used sluice box covers what to check on matting, riffles and the frame before you buy.