A Matter Of Class [1951]

There was a time when any spectator who couldn't identify the different classes racing at a power boat regatta would have been suspected of being a foreign agent hiding in the crowd. Only three or four classes raced at any one place and very few more than that even existed. In this year of 1951, however, any casual spectator able to identify every class appearing at a regatta must have a touch of genius about him. At the moment, there are more than 50 separate classes recognized by the American Power Boat Association. While not all are intensely active, and not all race throughout the nation, they are so numerous as to cause no little confusion as to their identity.

Recognition of the class of any inboard boat is not too difficult since the racing numbers on inboard craft carry either prefix or suffix letters to denote the class. Unfortunately, such is not the case with the outboards. The letters accompanying the racing numbers on the portable power plant outfits indicate the area from which the boat hails. Class recognition here is as keen a test of visual acuity as is the recognition of foreign aircraft. Your only hope is to spot them from the schedule of events or hope that the public announcement system will come to your rescue.

Even after you have determined the class in which a boat belongs, you normally have to search through the A.P.B.A. Year Book to find what the class title means in terms of size, power, cost, and the like. With the hope that we can save you such a search, we have summarized in these tables the main characteristics of the more active racing classes.

The A.P.B.A. classifies racing boats according to type of power plant (inboard or outboard) and hull design (runabout or hydroplane). The distinction between inboard and outboard motors surely requires little amplification in this day and age. The racing rules define an outboard as an internal combustion engine, complete with drive shaft and propeller, which can be attached to a boat and removed therefrom by human power. All other motors are considered to be inboard.

Inboard Runabouts
Suffix Class Min. length Max. cu. in. piston disp. Max. Engine price Degree of hop-up allowed
A A Racing None 100 $550 Considerable
B B Racing None 136 $700 Considerable
B B Service 15' 0" 152 None Some
C C Racing None 175 $850 Considerable
C C Service 15' 5" 190 None Some
D D Racing None 222 $950 Considerable
D D Service 15' 7" 235 None Some
E E Racing None 246 $1,250 Considerable
E E Service 16' 8" 255 None Some
M F Racing None 350 $1,500 Considerable
M F Service 18' 6" 370 None Some
N G Racing None 420 None Considerable
N G Service 21' 5" 550 None Some
H H Racing None 700 None Considerable
H H Service 24' 0" 779 None Some
I I Racing None 850 None Considerable
I I Service 24' 0" 950 None Some
J J Racing None 1025 None Considerable
K K Racing None Unlim. None Considerable
JS Jersey Speed Skiff 16' 0" 255 $1,500 Considerable
P Crackerbox 13' 6" 267 $750 Considerable
Z 48 cu. in. 9' 0" 48 $350 Some


Inboard Hydroplanes
Prefix Class Min. length Max. cu. in. piston disp. Max. engine price Degree of hop-up allowed
A 135 13' 6" 136 $1,000 Considerable
B 151 13' 6" 151 None No limit
F 225 16' 0" 266 $1,250 Considerable
G Gold Cup 10' 0" None None No limit
H 7 liter 19' 0" 427 (*) No limit
L 91 12' 0" 91.5 $600 Considerable
N 225 Div. H 16' 0" 225 $600 Considerable
O P.O.D.H. 13' 0" (**) None Limited
Y 48 9' 0" 48 $350 Some
U Unlimited None None None No limit
* — Unsupercharged $2000; supercharged $2500.
** — Ford V-8 60 only.


Outboard Racing Hydros
Class Piston displacement MM. weight of hull and controls MM. weight of hull, controls and driver
M Under 7.5 cu. in. 75 lbs. 200 lbs.
A 7.5-14 cu. in. 100 lbs. 250 lbs.
B 14-20 cu. in. 100 lbs. 265 lbs.
C 20-30 cu. In. 150 lbs. 315 lbs.
F 50-60 cu. in. 160 lbs. 335 lbs.


Outboard Runabouts — Service and Racing
Class Min. weight of hull and controls Min. total racing wt. less fuel and tools Min. length Min beam
C or smaller . 200 lbs 500 lbs. 13' 0" 4' 0"
F 225 lbs. 725 lbs. 13' 0" 4' 0"


Stock Outboard Hydros
Stock outboard hydros have been accepted as probationary classes in A, B, and D sizes. Hull rules are identical with those for racing hydros of the appropriate sizes; motor rules are the same as those for stock utilities of corresponding size.


Stock Utility Outboards
Class Max. piston displ. Min. seating capacity Min. weight of hull and controls Min. additional weight
JU 10 cu. in. 3 Seven pounds per cu. in. of motor displacement. 115 lbs.
AU 15 cu. in. 4 125 lbs.  
BU 20 cu. in. 4 135 lbs.  
CU 30 cu. in. 5 145 lbs.  
DU 40 cu. in. 5 155 lbs.  
EU 50 cu. in. 5 165 lbs.  
FU 60 cu. in. 5 175 lbs.  
NOTE: Overall racing weight (seven lbs. per cu. in. plus minimum additional weight) includes driver and hull with permanent hardware, but excludes motor, fuel and loose equipment.

The dividing line between runabouts and hydroplanes is not quite so evident. In general, a runabout is any hull of either displacement or monoplane type, having no steps or breaks in its bottom to create multiple planing or riding surfaces. Any hull unable to meet the runabout requirements is considered to be a hydroplane.

INBOARD HYDROPLANES are generally the fastest and most spectacular of racing classes. During the 1950 season (1951 figures still being incomplete), there were 482 inboard hydros registered with A.P.B.A. Most popular of the classes in this category was the 135 group with no less than 147 registered craft. Almost all of these were powered with Ford V-8 60 engines, the little eights which you may remember from some Fords built between 1937 and 1940. Although long obsolete for automobile use, a fantastic amount of hopping-up has boosted their mile record to 97.351 m.p.h.

Neck and neck in popularity are the 225s and the Div. II 225s, with 84 and 86 registrants respectively. You will note in the table that the 225s have a piston displacement ceiling of 266 inches. This and somewhat more lenient motor rules distinguish them from the Div. II boats. The latter are generally powered with earlier model Ford V-8s. With a 94 mile an hour record in the books, the "Hs" suffer by comparison with the smaller 135s and are really outclassed by the 225s and their 115-mile standard. Most of the 225s rely on beautifully reworked Mercury engines.

A relatively new, but fast-growing class is made up of the little 48s. A natural for the diminutive Crosley auto engine, these midgets of the inboards are spectacular out of all proportion to their size. Their record for the measured mile has zoomed to a shade under 72 m.p.h. During 1950, 75 boats were registered in this class.

Thirty-eight boats made up last year's combined Gold Cup and unlimited fleet. Although the two classes have different technical rules, most existing boats qualify under both codes. The most popular power plant here is the 1710 cubic inch Allison engine built for fighter aircraft. The big fellows have chalked up a mile record of 160.323 m.p.h.—the fastest man has ever traveled on water.

Costs of the various inboard boats are difficult to estimate in this period of unstable economy. If the necessary materials were available, you could probably put together a good 48 outfit for about $1,000, while an unlimited job could set you back $25,000 or more.

INBOARD RUNABOUTS, while comprising a large number of assorted classes, were only able to muster 232 registered boats during the past season. Fundamentally these are supposed to be the sort of boats you buy for family utility purposes (Service), and higher speed variations of that type (Racing). Writing effective rules has proved such a chore over the years that arguments and ill-feeling have kept down the interest in this category.

Fifty-five runabouts last year were in Class E Racing which is nicely suited for powering with a Gray Fireball or a hopped-up Ford V-8. The E mile record of 70.79 m.p.h. is the highest inboard runabout speed. Next in order of popularity is the 48 class which, like its hydroplane namesake, is made to order for the Crosley engine. These little fellows have run in excess of 53 miles an hour.

Class B Racing and the Cracker Boxes accounted for 24 registrants each. The Bs undoubtedly thrive because they use the same power plant as the popular 135 hydros, although their record speed is only 60.43. Cracker Boxes, low-cost outfits with power plants much the same as those in 225s, have exceeded 6833 in mile trials.

Runabout costs are likely to be as high, or higher, than the price tags on hydros of comparable engine size, but the speeds are understandably much slower, putting a further damper on popularity.

OUTBOARD RACING HYDROPLANES, 689 strong in 1950, constitute what may be a vanishing category. Relying for power on Evinrude and Johnson racing engines which were discontinued before the last War, these classes have continued largely by dint of the enthusiasm and skill of their owners and various racing mechanics. The most popular class—C hydros with 200 registrants—has a mile record of 63.549 m.p.h. The As—of which 176 registered last year—have topped 50. The Bs, with a 57-plus standard, drew 156 boats in 1950.

OUTBOARD RUNABOUTS comprise a category built around the same engines used in the hydros, plus monoplane hulls; 326 such outfits were on the A.P.B.A. list at the close of last season, with more than half of that total being in C Service class. This class boasts a record of 51.6 m.p.h.

STOCK UTILITY OUTBOARDS were by far the most popular of the racing categories, with no less than 1536 registered last year. Originally the utilities were intended to be outfits consisting of regular production outboard motors and hulls of the family or fishing type. Possibly encouraged by the growth of utility racing in the past few years, there have appeared on the market several motors with speed.

(Reprinted from Yachting, July 1951)