Review of Dehler 34 Mk II

Both the hull and the deck is made of hand laid fibreglass. Generally, a hull made of hand laid fibreglass requires only a minimum of maintenance during the sailing season.
The deck is a double deck which improves the indoor climate.

The boat is equipped with 3 cabins, 6 berths, a galley and toilet facility.

The boat has more than one rig.

One option is a fractional rig. A fractional rig has smaller headsails which make tacking easier, which is an advantage for cruisers and racers, of course. The downside is that having the wind from behind often requires a genaker or a spinnaker for optimal speed.

The Dehler 34 Mk II is equipped with a fin keel. The fin keel is the most common keel and provides splendid manoeuvrability. The downside is that it has less directional stability than a long keel.

The keel is made of iron. Many people prefer lead keel in favour of iron. The main argument is that lead is much heavier than iron and a lead keel can therefore be made smaller which again result in less wet surface, i.e. less drag. In fact iron is quite heavy, just 30% less heavy than lead, so the advantage of a lead keel is often overstated. As the surface of a fin type keel is just a fraction of the total wet surface, the difference between an iron keel and a lead keel can in reality be ignored for cruising yachts.

Dehler 34 Mk II can enter most marinas as the draft is just about 1.70 - 1.80 meter (5.58 - 5.88 ft) dependent on the load. See immersion rate below.

The boat is typically equipped with an inboard Yanmar 2G 20 diesel engine at 18.0 hp (13 kW), which gives a max speed about 5.4 knots.

The transmission is a shaft drive. A shaft drive will in the long run require less maintenence than other types of drive e.g. a sail drive.

The fuel tank which is made of stainless steel has a capacity of 60 liters (15 US gallons, 13 imperial gallons).

What is Capsize Screening Formula (CSF)?

The capsize screening value for Dehler 34 Mk II is 2.11, indicating that this boat would not be accepted to participate in ocean races.

What is Theoretical Maximum Hull Speed?

The theoretical maximal speed of a displacement boat of this length is 7.1 knots. The term "Theoretical Maximum Hull Speed" is widely used even though a boat can sail faster. The term shall be interpreted as above the theoretical speed a great additional power is necessary for a small gain in speed.

The immersion rate is defined as the weight required to sink the boat a certain level. The immersion rate for Dehler 34 Mk II is about 195 kg/cm, alternatively 1097 lbs/inch.
Meaning: if you load 195 kg cargo on the boat then it will sink 1 cm. Alternatively, if you load 1097 lbs cargo on the boat it will sink 1 inch.

What is Motion Comfort Ratio (MCR)?

The Motion Comfort Ratio for Dehler 34 Mk II is 19.4.

Comparing this ratio with similar sailboats show that it is more comfortable than 15% of all similar sailboat designs. This is a comfort value significantly below average.

What is L/B (Length Beam Ratio)?

The l/b ratio for Dehler 34 Mk II is 3.12.

Compared with other similar sailboats it is more spacy than 62% of all other designs. It seems that the designer has chosen a slightly more spacy hull design.

What is a Ballast Ratio?

The ballast ratio for Dehler 34 Mk II is 44%.

This ballast ratio shows a righting moment that is higher than 69% of all similar sailboat designs. A righting moment (ability to resist heeling) just above average.

What is Displacement Length Ratio?

The DL-ratio for Dehler 34 Mk II is 188 which categorizes this boat among 'light racers'.

79% of all similar sailboat designs are categorized as heavier. A light displacement requires less sailarea and has higher accellerations.

When buying anti-fouling bottom paint, it's nice to know how much to buy. The surface of the wet bottom is about 33m² (355 ft²).
Based on this, your favourite maritime shop can tell you the quantity you need.

Note: If you use a paint roller you will need more paint than if you use a paintbrush.

If you need to renew parts of your running rig and is not quite sure of the dimensions, you may find the estimates computed below useful.

This section is reserved boat owner's changes, improvements, etc. Here you might find (or contribute with) inspiration for your boat.

Do you have changes/improvements you would like to share? Upload a photo and describe what you have done.

We are always looking for new photos. If you can contribute with photos for Dehler 34 Mk II it would be a great help.

If you have any comments to the review, improvement suggestions, or the like, feel free to contact us. Criticism helps us to improve.

[Ref 1]: ISO 8666 Small craft — Principal data.
[Ref 3]: ISO 12215-5 Small craft — Hull construction and scantlings.