Review of RM 890

The boat is equipped with 120.0 liter fresh water capacity.

The RM 890 is equipped with 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 gennaker or a spinnaker for optimal speed.

Fin keel

The RM 890 is equipped with a fin keel. A boat with a fin keel is more manoeuvrable but has less directional stability than a similar boat with a full keel.

The boat can enter most marinas as the draft is just about 1.50 - 1.60 meter (4.92 - 5.22 ft) dependent on the load. See immersion rate below.

What is Capsize Screening Formula (CSF)?

The capsize screening value for RM 890 is 2.34, 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 7.2 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 RM 890 is about 201 kg/cm, alternatively 1129 lbs/inch.
Meaning: if you load 201 kg cargo on the boat then it will sink 1 cm. Alternatively, if you load 1129 lbs cargo on the boat it will sink 1 inch.

What is Motion Comfort Ratio (MCR)?

The Motion Comfort Ratio for RM 890 is 14.9.

Comparing this ratio with similar sailboats show that it is more comfortable than 12% 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 RM 890 is 2.60.

Compared with other similar sailboats it is more spacy than 92% of all other designs. It seems that the designer has chosen a significantly more spacy hull design.

What is a Ballast Ratio?

The ballast ratio for RM 890 is 30%.

This ballast ratio shows a righting moment that is higher than 5% of all similar sailboat designs. A righting moment (ability to resist heeling) significantly below average.

What is Displacement Length Ratio?

The DL-ratio for RM 890 is 130 which categorizes this boat among 'ultra light racers'.

93% of all similar sailboat designs are categorized as heavier. A light displacement requires less sailarea and has higher accellerations.

SA/D (Sail Area Displacement ratio)
Indicates how fast the boat is in light wind:
- Cruising Boats have ratios 10-15
- Cruiser-Racers have ratios 16-20
- Racers have ratios above 20
- High-Performance Racers have ratios above 24
Sail-area/displacement ratio (SA/D ratio): 23.40

When buying anti-fouling bottom paint, it's nice to know how much to buy. The surface of the wet bottom is about 35m² (376 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 modifications, 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 RM 890 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.