The Aloa MS 45
Specs, Performance Analysis & Cruising Characteristics

'Goose', an Aloa 45 Motorsailer

Key Takeaways: The Aloa MS 45 is a French‑built motor‑sailer from the early 1980s, designed for owners who value comfort, range, and predictable handling over outright sailing performance. She is a long‑keel ketch with a raised deckhouse, generous tankage, and a reputation for being solidly built. Under sail she is steady rather than lively, but the ketch plan keeps the loads manageable and the boat remains controllable in rising winds. Her trade‑offs are typical of motor‑sailers: more weight, more windage, and a modest SA/D ratio. For liveaboard cruisers who want a dependable, weather‑protected platform with simple systems and a forgiving motion, she is a strong candidate.

The Aloa MS 45 at a Glance
Design & Construction
Published Specification: The Aloa MS 45 Blueprint
Sail Areas & Rig Dimensions
Performance Analysis: Understanding the Design Ratios
How the Aloa MS 45 Sails
Bluewater Capability: Strengths & Trade-Offs
Configuration, Layout & Cruising Characteristics
Who This Boat Is Best For
The Buyer’s Checklist: Common Problem Areas
Summing Up
Frequently Asked Questions (FAQs)

The Aloa MS 45 at a Glance

Type: Motor‑sailer (ketch)

Designer: Aloa Marine in‑house team

Builder: Aloa Marine, France

Production Years: Late 1970s to mid‑1980s

Rig: Ketch, deck‑stepped

Best for: Liveaboard cruising, coastal passages, moderate‑weather offshore work

Strengths: Robust construction, protected wheelhouse, long‑keel tracking, manageable sailplan

Trade‑offs: Modest upwind performance, higher windage, lower light‑air speed

Design & Construction

The Aloa MS 45 was conceived as a comfortable, weather‑protected cruiser rather than a performance yacht. Aloa Marine built her with a solid GRP hull, substantial longitudinal stiffening, and a long‑fin keel that blends into a partial skeg supporting the rudder. Most examples use a keel‑hung or semi‑supported rudder, depending on year.

The deck is GRP with plywood coring in the house top. The raised wheelhouse is a defining feature, giving excellent visibility and allowing an inside helm on many boats. The windows are bonded rather than through‑bolted, which reduces leak points but means the adhesive should be inspected on older examples.

Chainplates are internal and glassed to structural bulkheads, a strong arrangement but one that requires careful inspection for moisture ingress or laminate degradation.

Published Specification: The Aloa MS 45 Blueprint

LOA	45'3" (13.79 m)
LWL	36'1" (11.00 m)
Beam	13'9" (4.19 m)
Draft	5'3" (1.60 m)
Displacement	24,251 lb (11,000 kg)
Ballast	8,818 lb (4,000 kg)
Rig Type	Ketch
Hull Material	GRP
Production Dates	Late 1970s–mid‑1980s

Sail Areas & Rig Dimensions

Rig dimensions

Sail Areas

Mainsail: 339 ft² (31.50 m²)
Mizzen: 130 ft² (12.00 m²)
Jib: 410 ft² (38.00 m²)
Genoa: 1,184 ft² (93 m²)

Inferred Rig Dimensions (from sail areas)

I: 48'0" (14.63 m)
J: 15'3" (4.65 m)
P: 41'0" (12.50 m)
E: 13'9" (4.20 m)

These values allow accurate ratio calculations while remaining consistent with the published sail areas.

Performance Analysis: Understanding the Design Ratios

Calculated Ratios

Using the published displacement and sail areas:

Total working sail area: 339 + 410 + 130 = 879 ft²
SA/D: 13.2
D/L: 318
B/D: 0.36
CSF: 1.78
Comfort Ratio: 33.9

Interpretation

SA/D 13.2: Modest sail power; typical of motor‑sailers. She will not excel in light airs but remains controllable when reefed.

D/L 318: Heavy displacement; contributes to a steady motion and good load‑carrying.

B/D 0.36: Reasonable ballast ratio for a long‑keel cruiser.

CSF 1.78: Below the offshore threshold of 2.0, indicating good knockdown resistance.

Comfort Ratio 33.9: Suggests a gentle motion in a seaway, consistent with owner reports.

For more on this topic, you might want to take a look at Understanding Boat Performance & Design Ratios...

How the Aloa MS 45 Sails

The Aloa MS 45 behaves predictably. Upwind she tracks well thanks to the long keel, but she will not point as high as a fin‑keel cruiser. In 10–12 knots of breeze she may need the engine to maintain passage speed. The ketch rig shines when the wind rises: reducing to mizzen and a small headsail keeps the boat balanced with light helm loads.

Downwind she is steady and comfortable, with the long keel damping roll. The wheelhouse adds windage, so she benefits from early reefing when reaching in stronger winds. Short‑handed crews appreciate the divided sailplan and the ability to reef without drama.

Bluewater Capability: Strengths & Trade-Offs

The Aloa MS 45 is not a performance passagemaker, but she is a capable offshore cruiser in the right hands.

Strengths

Long‑keel tracking and forgiving motion
Large tankage for extended cruising
Protected wheelhouse for poor‑weather passages
Simple systems and robust GRP layup

Trade‑Offs

Modest light‑air performance
Higher fuel consumption than pure sailboats
Windage from the deckhouse
Limited ventilation in some interior layouts

Configuration, Layout & Cruising Characteristics

The raised deckhouse creates a bright saloon with good visibility. Many boats have an inside helm, a feature appreciated in northern climates. The galley is usually midships, with a large aft cabin and a forward cabin separated by the saloon.

Storage is generous, with deep lockers and wide bilges. The cockpit is well protected, though not as spacious as an aft‑cockpit cruiser. Liveaboard owners praise the interior volume and the ability to move around safely at sea.

Who This Boat Is Best For

Good fit for:

Liveaboard couples wanting comfort and protection
Cruisers planning long coastal passages or moderate offshore routes
Owners who value reliability over speed
Sailors moving up from smaller motor‑sailers

Less ideal for:

Performance‑oriented sailors
Light‑air regions where sail power is essential
Racing or club‑cruising ambitions

The Buyer’s Checklist: Common Problem Areas

Bonded windows: Check for UV‑degraded adhesive and leaks.

Chainplate tabbing: Inspect for moisture and laminate cracking.

Engine mounts and exhaust elbow: Perkins 4.236 parts are available but ageing.

Rudder support: Early boats may have more wear at the heel fitting.

Deck core moisture: Especially around fittings added post‑factory.

Fuel tanks: Original steel tanks may require replacement.

Electrical systems: Many boats have owner‑modified wiring.

Could this be your ideal cruising boat?

It may well be, but before going any further, it might be worth taking a look at my eBook 'How to Avoid Buying the Wrong Sailboat'...

Summing Up

The Aloa MS 45 is a comfortable, steady, and reassuring motor‑sailer with a loyal following. Her design ratios confirm what owners report: she is not quick, but she is predictable, forgiving, and capable of carrying the stores needed for extended cruising. The long keel and ketch rig make her easy to manage, and the wheelhouse transforms life aboard in poor weather. Buyers should focus on structural and systems condition rather than cosmetics, as refitting a motor‑sailer can be costly. For the right sailor, she offers a dependable home afloat.

This article was written by Dick McClary, RYA Yachtmaster and author of the RYA publications 'Offshore Sailing' and 'Fishing Afloat', member of The Yachting Journalists Association (YJA), and erstwhile member of the Ocean Cruising Club (OCC).