Tri Sea Pearl 21 Buyer's Guide
Shopping for a used Tri Sea Pearl 21 means shopping for a shallow-water trailer sailor first and a cruiser second. The 21-foot trimaran from Marine Concepts was built to float where other keelboats ground out, and the used fleet reflects that brief: centerboard trimaran models with kick-up rudders, easily stepped twin masts, and a layout built around an open forward cockpit rather than an enclosed cabin.
Layouts on the Used Market
On the brokerage market you will find the Tri in its trimaran form with a 14-foot beam and a centerboard, alongside the rarer monohull and Tri-Sport siblings. The defining layout point for the monohull is the absence of a centerboard trunk thanks to leeboards, which leaves the forward cockpit free as a seating or overnight space protected by an optional cabin top. The single-hull variant shows a ten-foot mid cockpit and a six-foot-six aft cockpit; the trimaran shares the same open-plan logic. With boards up the boat draws well under a foot, and the easy-to-fill ballast tanks under the deck let a new owner adjust stability without permanent lead.
Equipment and Common Upgrades
The one piece of gear commonly fitted across the used fleet is a bimini, which matches the factory optional cabin top as rain protection for the forward cockpit. Beyond that, buyer-consequence upgrades tend to cluster around power and energy — a small outboard sized to the 950-pound hull — and sail handling, where the unstayed cat-ketch masts furl the sails directly and step without overhang. Navigation needs stay minimal given the boat's sheltered-water mission, and most comfort additions are limited to the canvas already noted.
What to Inspect
The construction is hand-laid fiberglass over Corecell with no wood to rot, so rot in structure is not the concern it would be in an older wooden tender anchor. Check the under-deck ballast tanks for clean fill-and-drain operation, since they are the boat's primary ballast system and a stuck valve changes handling anchor. On centerboard models, confirm the board and kick-up rudder move freely and show no impact damage from the shallow grounding the design invites anchor. The deck and liner are integral, so inspect the joint for crazing or separation.
Availability and Buyer's Takeaway
The typical market for these boats is the United States. For a buyer, the short checklist is: confirm configuration (Tri centerboard versus leeboard mono), verify ballast tanks cycle easily, and look for a bimini or cabin top as the standard weather option. A used Tri Sea Pearl 21 rewards the owner who wants launch-ramp cruising and river or shoal exploration over bluewater range.
Price & volume trends
Monthly asking-price and listing-volume trends for the Tri Sea Pearl 21. The line shows the median ask each month; the bars show how many listings appeared.
Monthly breakdown · 4 rows
| Month | Listings | Median ask | Δ vs. last mo. |
|---|---|---|---|
| Mar 25 | 1 | $8,000 | — |
| May 25 | 1 | $10,000 | +25.0% |
| Sep 25 | 1 | $8,000 | -20.0% |
| Apr 26 | 1 | $3,000 | -62.5% |
Where they're listed
Tri Sea Pearl 21 listings appear across 1 country. United States has the most listings with 2.
Country view
2 listings · 1 country| Country | Median ask | Listings · 12 mo | Active · 90 d | Share |
|---|---|---|---|---|
| United States | $5,500 | 2 | 0 | 100.0% |
Comparable models
Similar length, displacement, and era. Open a row to compare that model's market page.
Similar boats to compare
4 similar designs| Model | LOA | Median ask | Listings · 12 mo | Active · 90 d |
|---|---|---|---|---|
| ETAP 21i | 21.52' | $ 16,304 | 33 | 11 |
| Mirage Mirage Tandem Island | 18.5' | $ 5,950 | 15 | 5 |
| Parker Boats 21 | 21' | $ 5,231 | 8 | 1 |
| Mariner Sea Pearl 21You are here | — | $ 5,500 | 2 | 0 |