Hydro 28 Buyer's Guide
The Hydro 28 is a David Thomas-designed fiberglass sloop that Seaglass built from 1978, a fractional-rig coastal boat with a lead fin keel and transom-hung rudder. On the used market she presents as a small light-displacement racer-cruiser, and a buyer should follow the published dimensions rather than an assumed cruising checklist.
Layouts on the Used Market
A 10-foot beam over a 23-foot-9-inch waterline makes a compact volume for single-handed or couple coastal use. Board each candidate to judge liveability, since no authoritative layout taxonomy previews the plan. The load-dependent draft of 5.58 to 5.88 feet keeps the boat within most marina depth limits, a useful trait when assessing where you can keep her.
Equipment and Common Upgrades
The boat carries a fractional sloop rig with jib and genoa sheets of 27.9 feet and a mainsheet of 69.8 feet, all 3/8-inch, plus 61.4-foot spinnaker sheets of the same size anchor. Running rigging is a single-standard replacement job, so any upgrade question is about winches and sail inventory rather than line sizing. The 279 square-foot wetted bottom is a manageable area for antifouling and inspection.
What to Inspect
Confirm the solid fiberglass hull without core, check fin keel and transom-hung rudder attachments for age-appropriate wear, and verify sheet lengths and 3/8-inch diameters match the design so you are not buying a re-rigged outlier. Inspect the 279 square-foot bottom for condition as on any solid-glass hull, and confirm the transom-hung rudder pivot is free of play.
Availability and Buyer's Takeaway
Watch general listings for used Hydro 28s. Before purchase:
- Verify solid fiberglass hull and lead fin keel
- Confirm rudder stock and transom-hung pivot for play
- Measure sheets against 27.9 / 69.8 / 61.4-foot specs
- Inspect 279 sq ft bottom for blistering
- Check draft within 5.58–5.88 ft
Price & volume trends
Monthly asking-price and listing-volume trends for the Hydro 28. The line shows the median ask each month; the bars show how many listings appeared.
Monthly breakdown · 1 row
| Month | Listings | Median ask | Δ vs. last mo. |
|---|---|---|---|
| Sep 26 | 2 | $1,319 | — |
Where they're listed
Hydro 28 listings appear across 1 country. United Kingdom has the most listings with 2.
Country view
2 listings · 1 country| Country | Median ask | Listings · 12 mo | Active · 90 d | Share |
|---|---|---|---|---|
| United Kingdom | $1,319 | 2 | 2 | 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 |
|---|---|---|---|---|
| Marlow-Hunter 28 | 28.01' | $ 16,745 | 18 | 5 |
| One-Off 28 | 28.18' | $ 39,052 | 12 | 1 |
| Laser 28 | 28.41' | $ 17,086 | 11 | 3 |
| Hydro 28You are here | — | $ 1,319 | 2 | 2 |