Intended as large, fast vessels with the endurance and speed to operate with the battle fleet, they gained notoriety and the nickname of "Kalamity class" for being involved in many accidents.

Only one ever engaged an enemy vessel, K-7 hitting a U-boat amidships, though the torpedo failed to explode with what has been described as typical "K" luck; K-7 escaped retaliation by steaming away at speed.

The submarines were made more dangerous because the eight internal bulkheads were designed and tested during development to stand a pressure equivalent to only 70 feet (21 m), risking their collapse if the hull was compromised at a depth below this figure.

K3 was the first of the class to be completed in May 1916, and trials revealed numerous problems, such as the aforementioned swivel tubes, and that their low freeboard and great length made them awkward to handle either surfaced or submerged.

An early criticism of the class questioned the wisdom of combining such a large hull with so great a surface speed, producing a vessel with the pace of a destroyer and the turning circle of a battlecruiser.

It was considered that with their 24 knots (44 km/h; 28 mph) of speed the submarines could turn and outrun almost any threat if they were attacked on the surface, dispensing with a need for a rapid dive.

Nevertheless, there were still problems with seaworthiness, such as that in a heavy storm, sea water could enter the boat through the short twin funnels and put the boiler fires out.

K3 held the unofficial record for maximum diving depth (266 feet [81 m]) following an uncontrolled descent to the bottom of the Pentland Firth.

Submariners were 'Volunteers Only,' and the class reputation as being designated 'K' for Kalamity (or Killer) did little to endear them to their crews, or provide a steady stream of volunteers.

Her higher casing almost cured the problems of seawater entering the boiler room, and improved ballast tank arrangements cut the diving time to 3 minutes 12 seconds to get to 80 feet (24 m).

Although the concept of a submarine fast enough to operate with a battle fleet eventually fell out of favour, it was still an important consideration in the design of the River class in the late 1920s.