SONAR
Specifications
Hull
| LOA | 23 ft |
| LWL | 19.92 ft |
| Beam | 7.83 ft |
| Draft | 3.92 ft |
| Displacement | 2,100 lb |
| Ballast | 930.1 lb |
| Hull speed1.34·√LWL | 6.0 kn |
Rig & Sails
| Iforetriangle height | 25 ft |
| Jforetriangle base | 8.9 ft |
| Pmainsail luff | 27.5 ft |
| Emainsail foot | 11.2 ft |
| FLforestay | 8.9 ft |
| Mainsail | 277.6 sq ft |
| Jib (100%) | 111.3 sq ft |
| Spinnaker | 189.1 sq ft |
About the SONAR
Commissioned by members of Noroton YC of Darien CT USA and first built by Seidelmann Yachts. A few were also built by Carbon Index in the UK. Current builder (2019) is Rondar Raceboats.
Performance
ORC Performance Data(14 certificates)
Measured performance data from ORC (Offshore Racing Congress) certificates.
Polar Diagram
Boat speed (kn) vs. true wind angle. Source: ORC
Racing Ratings
Triple Number
ORC Measured
Sail Areas (ORC)
Speed Table (kn)
| TWA \ TWS | 6 | 8 | 10 | 12 | 14 | 16 | 20 | 24 |
|---|---|---|---|---|---|---|---|---|
| 52° | 4.3 | 5.1 | 5.6 | 5.8 | 6.0 | 6.1 | 6.1 | 6.1 |
| 60° | 4.6 | 5.3 | 5.8 | 6.0 | 6.2 | 6.3 | 6.4 | 6.5 |
| 75° | 4.8 | 5.5 | 5.9 | 6.2 | 6.5 | 6.7 | 6.9 | 7.0 |
| 90° | 4.8 | 5.7 | 6.1 | 6.5 | 6.7 | 6.9 | 7.5 | 7.9 |
| 110° | 4.9 | 5.7 | 6.2 | 6.7 | 7.1 | 7.6 | 8.3 | 9.2 |
| 120° | 4.7 | 5.6 | 6.1 | 6.6 | 7.0 | 7.6 | 9.4 | 10.9 |
| 135° | 4.2 | 5.1 | 5.8 | 6.2 | 6.7 | 7.2 | 8.9 | 12.5 |
| 150° | 3.5 | 4.5 | 5.3 | 5.9 | 6.3 | 6.7 | 7.7 | 10.6 |
| Beat VMG | 2.8 | 3.4 | 3.8 | 4.1 | 4.2 | 4.3 | 4.2 | 4.1 |
| Run VMG | 3.1 | 3.9 | 4.7 | 5.3 | 5.8 | 6.2 | 7.0 | 9.2 |
Images
Pricing
We don't have market pricing data for the SONAR yet. If you own one, help other buyers — what did you pay for it? Reports build a community price estimate over time.
Estimated Cost of Ownership
Based on 23ft LOA. Actual costs vary by condition, usage, and local rates.
Known Issues & Pre-Purchase Inspection
We don't have enough data on the SONARyet to publish model-specific findings we'd stand behind — but here's a free general inspection checklist, built from our research into what actually goes wrong on boats of this kind.
Drawn from 7,029 documented issues across 2,391 models, ordered so the areas that most often turn up problems come first.
Own a SONAR? Reports from owners are what turn this into a model-specific checklist — and they're the reason the boats above it have one.
Similar Sailboats
Which engine powers your SONAR?
We haven't confirmed the engine for this model yet. If you own or know one, tell us — as owners report in, we build an accurate picture over time.
Already know your engine? Search all engines → to find its exact parts.
Used sails that fit the SONAR
Checking eBay for sails sized to this boat's rig…