In March 1885, a local resident, Miss Willis, died suddenly after dancing at a ball in Erith with a porter from the Hospital ships.  Her cause of death, noted by a local doctor as 'malignant smallpox' (she had died of haemorrhage within three hours of onset) was contested by the ships' physician, who also asserted that the crew followed a strict protocol of precautionary measures when leaving their duties.  The diagnosis was never confirmed but, following this incident, MAB introduced a policy that the ships would receive supplies through the River Ambulance Service rather than be purchased locally or sent by rail.

The paddle steamers were often out of commision.  Collisions between them (their protruding paddles were particularly vulnerable) and the wharves and other vessels were frequent.  On 31st December 1888 the steamship River Derwent of Glasgow, after having sunk a vessel just below the Blackwall Reach, fouled the hulk Benmore and the Maltese Cross secured alongside, slightly damaging the latter.  The forward bitts (pair of posts for fastening cables) were torn away and the after bitts damaged.

In 1892 there was another smallpox epidemic.  By this time MAB also owned the Swallow, a steam pinnace.  The Geneva Cross, a new purpose-built ambulance steamer built in 1894, necessitated the replacement of the hulk Benmore by mooring dolphins.  At her stern the Geneva Cross had an upper cabin with two compartments for 16 acute patients and a lower cabin with two compartment for 36 patients.  Visitors could travel in a fore cabin.

In 1896 a new ambulance steam launch, the White Cross, replaced the Swallow.  The Red Cross was sold in 1897 for £450 and the money put towards the cost of the White Cross.

By 1898 the River Ambulance Service had three ambulance steamboats - the Maltese Cross, the Albert Victor and the Geneva Cross - and the ambulance steam launch, the White Cross.  In that year the Service carried 955 passengers (compared with 1293 in 1897); these comprised 6 patients (69 in 1897), 5 recovered patients (55 in 1897) and 944 visitors, staff and workmen (1159 in 1897).

During the next smallpox epidemic of 1901, MAB began to build a permanent land-based smallpox hospital.  Two temporary hospitals - the Long Reach Hospital (with 300 beds) and the Orchard Hospital (800 beds) - were built during this time and opened at the beginning of 1902.  In the same year another vessel, the Red Cross II, had been bought from the London and South Western Railway.  Originally named the Solent, she had been built as a 300-seat passenger vessel.  She was converted to hold 68 beds.

The hospital ships remained in use until the Joyce Green Hospital (with 940 beds) was completed in 1903.  The River Ambulance Service continued, with patients disembarking at Long Reach pier, then being being transported by horse-drawn ambulance (later horse-drawn tram cars) to hospital.  

During 1925-1926 the running costs of the River Ambulance Service were £7,547.

In 1930 the LCC took over control of the Service from MAB.  In July a vessel collided with the Albert Victor and a mooring dolphin at South Wharf.  After this incident, patients (some 200 a month) were transported by land ambulance rather than via the river to Long Reach.

The River Ambulance Service terminated in 1933.  In February and March the steamers left South Wharf for mooring at Erith, prior to disposal, following disinfection and certification by the Port Sanitary Authority.