Spectrum #28: Order these submarine milestones by year — the solution
The Spectrum puzzle from September 11, 2026: six things on one hidden scale, earliest to latest, with every figure and where the checks were best spent.
The puzzle
Order these submarine milestones by year, earliest at the top and latest at the bottom. The board opened in this order:
- H.L. Hunley
- USS Nautilus launched
- Alvin
- USS Holland
- Trieste dives the Challenger Deep
- The Turtle
Trieste dives the Challenger Deep was already in place; The Turtle opened 5 places from home.
The walkthrough
The ends first. The Turtle is the earliest of the six at 1776 and Alvin the latest at 1964. Anchor those and the middle four are what is left to place.
Where the scale splits. The widest gap is between The Turtle (1776) and H.L. Hunley (1864) — 88 years apart. Everything above that line belongs on the earliest side and everything below it on the latest side, so sorting the six into those two groups is most of the puzzle.
The closest call. Trieste dives the Challenger Deep (1960) and Alvin (1964) are only 4 years apart — the pair that is a coin flip without the figures, and the place to spend a check: a check locks whatever is already right and leaves only the wrong tiles to swap.
The answer
| # | Earliest to Latest | Figure |
|---|---|---|
| 1 | The Turtle | 1776 |
| 2 | H.L. Hunley | 1864 |
| 3 | USS Holland | 1900 |
| 4 | USS Nautilus launched | 1954 |
| 5 | Trieste dives the Challenger Deep | 1960 |
| 6 | Alvin | 1964 |
Previous: Spectrum #27 (Thu, Sep 10) · Next: Spectrum #29 (Sat, Sep 12)
About Spectrum
Spectrum is Noggin’s daily ordering puzzle: six things, one hidden scale, three checks. Tiles in the right place lock green; the figures turn over when the board is done. How to play Spectrum, or play today’s.