Labeling System


Any comments, criticisms, suggestions or contributions will be greatly appreciated.
Thanks in advance.

Write to:   g.gefaell<at>    (Substitute <at> by @)

Searching for effective formulae to define motorsailers, I've come to find what I think is a better aproach to the "century" labeling system, to classify all kind of monohulled sailing boats with an engine.

My first approach (04.06.2005) for such a labeling system for all boats with engine and sails, was something like:


Letter relates to the number of hulls: M: Monohull; C: Catamaran; T: Trimaran

Number after letter is the closest integer number for (D/L ratio)/10. So 250 would be just 25;  372 would be 37, etc.

First figure in fraction: Closest integer number of the SA/D ratio, so 14.76 would be just 15.

Second figure in fraction: Closest integer number for HP*1000/D. So 2.35 would be just 2;   3.65 would be 4, etc.

Maybe this system is somewhat "connoisseurs" oriented, but I think it give us a more accurate idea of the boat's capabilities than the XX/YY  system.

Then (12.06.2005), analizing 45 monohulled motorsailers from 25 to 54 feet, I have found that dividing the SA/D ratio by 6 times the HP/D ratio, the result should be around one (1.00) for what I understand as proper 50/50 (90/90?) oceangoing motorsailors.

I decided to stick to monohulled boats, as multihulled boats is a different breed (Label and Interpretation for them under study)

So we may use, to compare things, the SA/D ratio against 6 times the HP/D ratio in the labeling system I proposed before, so the "fraction" into the label give us a better idea about the relation among the relative power of sails vs. engine.

So, a monohull with a D/L ratio of 356, an SA/D ratio of 14.45 and an HP/D ratio of 2.3, would have a label like:  35-14/14

A better option to simplify the labeling, is to express the D/L ratio as a range (Light, Medium, Heavy, etc), so we could label the boat with the ratios upwards mentioned as:

H 14/14
This is my proposed all monohulled boats Short Labeling system.

First figure relates to the SA/D ratio (to the closest integer), so to the sailing power, and
Second figure relates to the 6*HP/D ratio (to the closest integer), so to the motoring power
Letter is related to the D/L ratio, as follows (monohulls):

VL = Very low D/L ratio, under 100
L= Low D/L, from 100 to 200, typically 150
M = Medium D/L, from 200 to 300, typically 250
H = High D/L, from 300 to 400, tipically 350
VH = Very Heavy D/L, over 400

Interpretation for monohulled motorsailers:

- If ratio in label is greater than one, the boat is sailing oriented. If less than one, motoring oriented.

- If first figure is 14+ the boat has plenty of power under sails alone.  Lower than 10 seems too low sail power to me for a motorsailer: The boat should rather be considered a "sail assisted motor boat". Higher than 16 the boat should probably be better classificated as a sailing boat, with more or less engine power.

- Second figure being over 18 usually means quite an excess of engine power, in my opinion. For an efficient motorsailer, it should be around 14, let's say from 12 to 16.

- Second figure being under 10 indicates a pure auxiliary sailboat.

- What are called  50/50  motorsailers by the "century" rule, become 14/14 (more or less) under this labeling system.

The benefit of this labeling system, against the "century" rule, is that saying that a boat is a 50/50 motorsailer says nothing about the real sail and engine power of the boat, nor if she's light or heavy, while this new label I propose really does.

Now we can even add some letters at the end of it, to better explain the intended design (Or marketing!) concept, as MS for Motorsailers, PH for Pilot House, RS for raised saloon, OC for ocean cruiser, CC for coastal cruiser, etc, etc.

So, if we read something like M 16/12 RSOC, we can understand the boat is a "medium weight, sail oriented, raised saloon ocean cruiser" most probably with a good performance under sail and with an engine allowing for economic motoring passages but having yet enough power reserve to beat to winward in a gale in protected waters.

Going further, we can try to look for how to better enphasize and define some subtle but most important differences like the ones between boats labeled as M 14/14 CCPH and M 14/14 OCPH. To this end, and using what's already available in the industry, we can add the UE Category Design letter (A, B, C, D) which in a very precise way defines the designed weather-coping ability. So we arrive to the very precise:

Full Labeling System
We have labeled here a real ocean going, medium weighted, sail oriented, efficiently engine-powered, pilothouse motorsailer.

A whole lot of a definition. And a whole lot of a boat.

For those not familiarized with the UE Design Category, here you have the meanings:

- A, applies to boats designed to cope with winds in excess of force 8 and waves over 4 m. Oceanic.
- B, to boats designed to cope with winds up to force 8 and waves up to 4 m.  Short open seas passages.
- C, to boats designed to cope with winds up to force 6 and 2 m waves. Coastal sailing.
- D, to boats designed to navigate in protected waters, maximum force 4 and 0,5 m waves.

In some European countries you are allowed to sail only within a zone defined by the local authorities, based on the Design Category and the safety equipment carried aboard. In Spain, with the proper safety equipment, you have no restrictions for a boat labeled "A"; you can go off to 60 miles from a shelter for category "B"; 25 miles for category "C" and 5 miles, in sheltered waters only, for category D