An underwater survey enquiry often starts with a vessel name and a port. That is enough to begin a conversation, but not enough to define the work. The survey team needs to understand which vessel will attend, why an inspection is required, what areas are involved and which organisation will accept the results. Preparing that information early reduces avoidable clarification during a short port call.

This guide concerns the information package prepared by the vessel or superintendent. It is not a diving procedure or an assurance that an in-water inspection will satisfy a docking requirement. Acceptance, survey scope and operational arrangements must be confirmed with the relevant class society, flag administration where applicable, port and competent service provider.

Give the vessel a reliable identity

Include the current vessel name, IMO number where assigned, flag, class society and the responsible management contact. A name alone is vulnerable to spelling variations and changes of ownership. Put the same identity on the enquiry, drawing list and supporting reports so the recipient can establish that every document belongs to the correct vessel.

Add the principal dimensions and relevant vessel type, but identify the source and revision of technical particulars. Do not copy a sister vessel’s information without confirming that it applies. A practical cover sheet can also identify the person authorised to answer technical questions and the local agent handling attendance arrangements.

State the purpose before listing the equipment

Distinguish a class-related bottom survey from a condition inspection, damage investigation or a commercial hull assessment. These enquiries can involve similar underwater areas while requiring different evidence and acceptance arrangements. If a survey instruction exists, send its exact reference rather than paraphrasing it as “full underwater survey”.

For context, DNV’s in-water bottom survey page explains that in-water inspection can serve as an alternative to drydocking under the relevant conditions. Its discussion also addresses mobile offshore units and surveyor supervision. This is not blanket permission for every vessel or attendance. Ask the vessel’s own class contact to confirm the applicable route before treating a contractor’s quotation as evidence of acceptance.

Use the current survey status

Check the latest class status, relevant outstanding items and the particular survey requested. DNV’s vessel status guidance, for example, describes access to certificates, survey items, follow-up records and supporting documents. Other societies have their own arrangements. The purpose is to provide the current instruction, not a historical certificate bundle without context.

Make uncertainty explicit. If the superintendent is waiting for class confirmation, state that in the enquiry and identify the question still open. A service provider can assess availability while the scope is being clarified, but those two decisions should remain separate. Record subsequent confirmation in the same job file so the final attendance team receives it.

Choose drawings that answer real questions

Prepare a concise drawing index covering the areas included in the proposed scope. Depending on the vessel and job, the team may request an underwater arrangement, relevant appendage details or drawings identifying inspection locations. Let the responsible surveyor and provider specify what they need; sending every drawing available can obscure the useful information.

Use readable files with visible titles and revision references. When an old drawing has been superseded, remove it from the current package or mark it clearly as historical. If a modification has not yet been reflected in a drawing, disclose that limitation. A handwritten note on someone’s private copy should not be the only record of a change affecting the planned inspection.

Connect previous findings to identifiable locations

A photograph labelled “hull damage” leaves the recipient guessing where to look. Link previous observations to the vessel’s established location references, report number and inspection date. Describe what was observed and what action followed, keeping confirmed repairs separate from proposed work or unverified explanations.

Consider a hypothetical report that recommends checking a particular area again at the next opportunity. The useful package contains the recommendation, the location reference and any later close-out record. Simply attaching the previous report without pointing out the outstanding item risks losing the reason for the new attendance among dozens of unrelated pages.

Describe the port-call assumptions honestly

Provide the intended port, berth or anchorage if known, expected arrival and departure, and the latest contact for changes. Mark provisional details as provisional. Explain planned operations that may affect access or the attendance window, allowing the provider and vessel management to assess coordination requirements through their own procedures.

A short commercial window should never be presented as a reason to bypass an operational assessment. If the berth changes or the job scope expands, circulate the revision rather than expecting the original quotation to cover the new situation. Keep a simple revision date on the enquiry package so everyone can identify the latest information.

Agree the report and the next decision

Before attendance, clarify who needs the report, what evidence the accepting organisation requires and who will resolve any findings. DNV provides vessel-specific survey preparation notes through its portal. Where available, the equivalent instructions from the vessel’s society should guide the preparation discussion.

For an underwater-service enquiry to Offshore Marine Solutions, send a coherent package with vessel particulars, purpose, supporting references and port-call details. Good preparation does not guarantee a favourable survey result. It gives the responsible parties a clearer basis for deciding the scope, arranging attendance and documenting what remains to be done.