Mitigations

Prior to Port Call:

Crew and personnel should be aware of drug cartels and the risks involved in establishing communication with them.
Brief and remind all crew of the risks involved with engaging in drug smuggling operations and highlight the risks to their personal safety and well-being.
Establish record books before calling at port to accurately record all visiting port, health and police officials, as well as stevedores and the areas that were accessed on board the vessel.
Prepare vessel search plans in advance and modify and review as required in preparation for full vessel searches after leaving port and cargo operations have completed.
Consult with port security/officials beforehand, arranging appropriate security requirements as required.

Exercise heightened levels of caution and awareness when docked at port.
Strictly enforce single entry points onto the vessel, limiting vessel access to essential personnel only.
Enforce partial restrictions to movement aboard the vessel by external persons, restricting movement in engine rooms, holds, stores, and other areas of vulnerability.
Keep pre-arranged logbooks at the single point of entry/exit, and verify all external persons' appropriate details and paperwork before boarding.
Inform the Master or Chief Officer if the watch is uncertain as to whether an individual has legitimate reasons to be onboard.
Ensure a crew member / watchman is present where visiting personnel/stevedores are aboard the vessel, keeping areas of activity under surveillance, and reporting any suspicious behavior to the Master/Chief Officer.
Ensure watchmen are aware of all approaching/smaller vessels in the vicinity of the docked vessel, particularly after-hours under darkness.
Ensure surrounding waters are well-lit, recognizing smugglers may target the hull and rudder of a docked vessel to store/transport drugs.
Consider floodlights as supplementary to primary illumination systems, particularly if there is concern over a suspicious vessel/individual.

At what stage of transit are you most concerned about drug smuggling?

Prior to port call.
Whilst in port.
During cargo operations.
On completion of cargo operations.
Leaving port.

During Cargo Operations:

Perform partial vessel searches, with a full vessel search conducted when operations are completed.
Divide vessel searches between crew and cross-check, rotated randomly by the ship security officer.
Assume visiting persons have unrestricted access to the vessel when searching.
Prompt a reactive search in circumstances such as unauthorized personnel on board, personnel carrying parcels, entry points temporarily unmonitored, evidence of disturbed stowage, missing keys, or evidence of tampering with tank tops, boat covers, and unlocked restricted areas.
Inspect the vessel's hull below the waterline before departure to determine whether illegal substances have been attached to the vessel's hull or rudder, areas often targeted by smugglers.

On Completion of Cargo Operations:

Perform a full search of the vessel, including looking for illegal substances and stowaways.
Request a comprehensive vessel inspection, including inspection of the vessel's hull below the waterline, before departure if there are suspicions that drugs may have been placed onboard.
Conduct an anti-smuggling sub-aquatic survey to ascertain that no illegal substances are attached to the vessel below her waterline, which is the most common measure.

Leaving Port:

Conduct a full vessel search as the vessel leaves port.
Maintain vigilance when leaving port, identifying and reporting suspicious activity.
Be aware that inflatables and skiffs may approach a vessel to retrieve drugs attached to the external hull to avoid detection from coast guard and police forces patrolling the coast.

On Discovering a Suspicious Package:

Guidelines for Discovering Drugs on a Vessel as per IMO Resolution FAL.9(34)

The International Maritime Organisation (IMO) has provided guidelines to prevent and suppress drug smuggling on vessels. These guidelines suggest the following course of action if drugs are discovered on board the ship while at or leaving the port:
Verification: Before taking any action, it is necessary to have another person witness the position of a suspicious package or bag. If possible, photographs of the package or bag should be taken as found, and a witness should be sought.
Minimal Handling: As much as possible, handle the package or bag as little as possible, and be mindful that there may be fingerprint evidence on it.
Safe Removal: If necessary, take handling precautions, remove the goods to a safe place under lock and key, and guard them.
Record: If the discovery is made at sea, the vessel's log should record any details about the find, such as the date, time, location, approximate quantity, person detecting, names of witnesses, etc.
Confidentiality: Do not disclose the find and limit information to persons who need to know.
Notification: Before entering territorial waters, notify the competent authorities at the next port of call. Failure to do so could result in charges of drug trafficking.
Interview: Do not allow crew members to disembark before being interviewed by the competent authorities.
Protection: Protect any wrapping and anything else found in the space.
Further Search: Consider searching similar locations and spaces.
Reporting: Write a report as soon as possible after the event, including everything that occurred. Make a sketch plan of the space and area.

Would you find a regular report on maritime drug smuggling useful?

Yes, very much so.
There were some useful takeaways.
Not so relevant to me at this time.