The LALIZAS Signal Day Diamond (model 72732) is a rigid black day shape that sailing vessels display to signal their status under the International Regulations for Preventing Collisions at Sea (COLREGS). Measuring 47 3/16 x 23 5/8 in (1198.9 x 599.4 mm), it is hoisted forward where it can best be seen so that other vessels can identify your status by day, when navigation lights are not shown.
Day shapes are the daytime equivalent of navigation lights. Whether you are motorsailing, anchored, or constrained by your draft, the correct black shape hoisted in the rigging is both a legal obligation under COLREGS and a practical collision-avoidance signal that other mariners read at a glance.
Day shapes at a glance
| Day shape | What it signals | COLREGS reference |
|---|---|---|
| Cone (apex down) | Sailing vessel also using engine power (motorsailing) | Rule 25(e) |
| Diamond (two cones base-to-base) | Vessel constrained by her draft | Rule 28 |
| Ball | Vessel at anchor | Rule 30 |
| LALIZAS 72732 diamond | Rigid black diamond, 47 3/16 x 23 5/8 in (1198.9 x 599.4 mm) | Meets size minimums for vessels under 20 m |
What is the LALIZAS Signal Day Diamond and who needs it?
The LALIZAS Signal Day Diamond (72732) is a rigid black diamond shape, formed by two cones joined base-to-base, used aboard sailing vessels to communicate status during daylight hours. It measures 47 3/16 inches in height by 23 5/8 inches in width (1198.9 x 599.4 mm), giving it a clear, unambiguous silhouette that remains recognizable from another vessel's bridge at distance. The rigid construction holds its form in wind without collapsing, which is essential for a day shape to be read correctly.
Under COLREGS, the diamond is the shape displayed by a vessel constrained by her draft (Rule 28). Sailors also carry day shapes as part of a complete signaling kit: a cone (apex downward) for motorsailing under Rule 25(e), and a ball for lying at anchor under Rule 30. Any sailing yacht with an auxiliary engine — from a 30-foot coastal cruiser to a 50-foot bluewater passage maker — should carry the appropriate day shapes, and offshore racing under the Offshore Special Regulations (OSR) requires them as part of safety-equipment audits.
How do you display the LALIZAS day diamond correctly?
COLREGS specifies that day shapes are displayed "where they can best be seen." For most sailing vessels this means hoisting the shape on the forestay, an inner forestay, or a dedicated halyard forward, clear of the headsail and rigging so it is visible from all directions. The LALIZAS 72732 includes attachment points suitable for a halyard or lashing, and its near-48-inch dimension presents a silhouette that a vessel approaching from a mile away can identify even in poor contrast.
Day shapes are required only during daylight hours — between sunrise and sunset. At night COLREGS requires navigation lights instead: masthead steaming light, sidelights, and sternlight when under power, and sidelights plus sternlight when sailing. Remove the shape once it no longer applies to your situation, because a shape left flying creates a false signal that can confuse other mariners.
What are the specifications and which vessels does it fit?
The LALIZAS 72732 is sized to meet the COLREGS day-shape minimums for vessels under 20 meters (65.6 ft) LOA, which require a diamond at least 0.6 meters (about 23.6 inches) across its smallest dimension. At 47 3/16 x 23 5/8 in (1198.9 x 599.4 mm), the 72732 exceeds that minimum, making it suitable for the vast majority of privately owned sailing yachts.
| Vessel type / size | LOA | Compatible with LALIZAS 72732? |
|---|---|---|
| Coastal cruiser (e.g., Catalina 30) | 30 ft | Yes |
| Mid-range bluewater (e.g., Beneteau 40) | 40 ft | Yes |
| Offshore passage maker (e.g., Hallberg-Rassy 48) | 48 ft | Yes |
| Performance sloop (e.g., Swan 60) | 60 ft | Yes |
Why is LALIZAS a trusted name in marine safety?
Lalizas has manufactured marine safety equipment since 1982 and supplies naval authorities, coast guards, and commercial fleets in more than 100 countries. Its day shapes, lifebuoys, flares, navigation lights, and life-raft accessories are built to ISO and SOLAS standards, giving sailors confidence that a product like the 72732 will perform reliably. Choosing a recognized brand for day shapes and signaling gear reduces the risk of a failure during a flag-state inspection or, more critically, during a real situation where correct signaling helps prevent a collision.
Frequently asked questions
Is a day diamond the same as a day cone?
No. Under COLREGS a cone (apex downward) is shown by a sailing vessel also using engine power (Rule 25(e)), while a diamond is shown by a vessel constrained by her draft (Rule 28). They are different shapes signaling different situations, so a complete kit carries both.
What are the dimensions of the LALIZAS 72732?
It measures 47 3/16 x 23 5/8 inches (1198.9 x 599.4 mm), which exceeds the COLREGS 0.6-meter minimum for day shapes on vessels under 20 meters LOA.
When do I hoist the day shape and when do I take it down?
Day shapes are shown only between sunrise and sunset. At night you show the appropriate navigation lights instead, and you remove the shape as soon as the situation it signals no longer applies.
Is the 72732 durable enough for offshore use?
Yes. It is a rigid, weather-resistant black shape engineered to hold its form in wind and to withstand UV and saltwater exposure, consistent with Lalizas' ISO-compliant safety range.
Do I need other day shapes to be fully compliant?
Possibly. Depending on how you operate you may also need a ball (at anchor, Rule 30) and a cone (motorsailing, Rule 25(e)). Lalizas makes a full range of COLREGS day shapes so you can build a complete signaling kit.
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