In a previous post, I wrote about participating in an underway crew transfer. (That post can be found here: ) I had concerns about this maneuver at the time, and have since been looking into the subject.

Crew transfer while vessels are underway is not well covered, in either print seamanship resources or in materials that are easily found on the Internet. Most discussions on the Internet focus on transfers between large ships and smaller vessels. A few more specific references have turned up so far: the US Coast Guard Boat Crew Seamanship Manual; a caption underneath a photo in The Annapolis Book of Seamanship by John Rousmaniere; a manual for water taxi passenger transfer published by the Australian government; and various discussions of coming alongside for the purpose of rafting at anchor, which are found in some books and on the Internet (details and links are included farther down). As well, there are a number of Internet materials regarding crew transfer between small boats and large ships, and a fascinating manual and video of crew transfer between ships by way of a “highline.”

The preferred method of crew transfer between vessels underway is by use of a smaller dinghy between the larger vessels, if conditions allow. This avoids the problems of larger boats being thrown against one another by waves, with potential for damage to the boats and for injuries involving crushing of persons or limbs between the boats. It is my belief, though I have nothing specific to base this on, that these potential hazards of direct crew transfer may very well be the reason why the topic of coming alongside while underway, for the purpose of crew transfer, is so little discussed.

In spite of these issues, there can be situations where this maneuver is considered, or undertaken, whether because of dire need, or because people think that it is convenient. This author was involved in the latter, without a tremendous amount of forethought. Though the maneuver went just fine, it sure did inspire a lot of thought afterwards!

In hindsight, I think that this kind of maneuver is much more appropriate between smaller boats, such as daysailers, sailing dinghies and other lightweight craft, and that the hazards increase substantially as the two vessels together increase in size and displacement. This goes back to the preference for crew transfer between more substantial vessels being done via a smaller dinghy, to avoid the problems of two larger boats being thrown together by waves. Regardless, direct crew transfer between more substantial vessels has felt worth understanding more fully, because the possibility can arise.

Following is what I have learned, so far, from a good bit of reading and Internet search, and a moderate amount of discussion with a variety of experienced sailors. What is yet to be done is more discussion with those who are professionals in the field of boating and boating safety, some of whom routinely come alongside other vessels underway for various purposes. These include people engaged in commercial fishing, harbormasters, and those who provide small craft marine towing, and individuals working in the Coast Guard and various boating safety organizations. I’m going to keep working on those discussions, and will update this post with any information that I find. In the meantime, following is a list of considerations and procedures, assembled from a number of sources, each of which are referenced with initials in parentheses and included in full further below.

Crew Transfer Underway: Considerations and Procedure Notes – this is NOT an authoritative manual – see below (SL)

– Evaluate conditions, vessels, and personnel skills and physical abilities; determine whether maneuver is both possible and prudent in this situation; if planning to go ahead, double check conditions immediately before beginning procedure – it’s possible for conditions to change between the time of making the initial plan and the time when the maneuver is to be carried out. If conditions are no longer favorable, change the plan! (WC, AU, SL)
– discuss both the overall plan and specific procedures; confirm agreement regarding procedures between captains; verify that crew understands procedures (AU, CG)
– all participants should be wearing PFDs; crew who are transferring between boats, and crew providing transfer assistance on both boats, MUST wear PFDs. (AU) (CG – Coast Guard personnel on deck and underway wear PFDs at all times – it’s not a bad idea!)
– choose location away from traffic and hazards, with consideration for what will happen if there are complications that require more time than expected for the transfer to occur (AU, CG, SL)
– it is preferable if one of the boats (preferably the larger boat) is anchored (CF, SL)
– if anchoring is not possible, or is not desirable, evaluate waves/seas
– unless there is perfectly flat calm, both boats should be making way when the transfer occurs. This is because if hove-to, boats are likely to be severely bashed against each other by waves, resulting in damage and possible injury. Sailboats are more stable when under sail, and this is desirable if possible without rigging entanglement. (CG) If mismatched in size, smaller boat may sustain damage, particularly if transfer is carried out while not making way. (CF) Coming alongside while making way steadies both vessels, reducing potential for damage. (CG)
– Both boats should proceed at slowest speed that ensures steering for both boats. (AU, CG)
– if there is a substantial size difference, and both boats are maneuverable, smaller boat approaches larger boat (larger boat is more stable, and can more effectively hold steady course and speed through waves) (SL)
– approach is made to leeward of boat that is holding its course and speed. (See CG reference for exceptions, including when approaching boat is larger, and can create a lee for vessel holding its course and speed) (ABS, CG)
– if two sailboats, pay careful attention to the rigging of one boat being offset from the rigging of the other boat, to prevent entanglement and breakage of rigging. Masts have been lost… (CF, as well as numerous other guidelines for rafting available on the Internet)
– if at least one boat is powered by sail alone, and transfer will be done while making way, consider doing maneuver on a heading that provides a beam reach, for best speed control and maneuverability of sail-powered vessel (SL)
– If neither boat is an inflatable, several closely spaced fenders are placed where the boats will meet, (ABS, CF) with extra fenders beyond where the contact is expected; one boat or the other should be fendered, but not both (if both boats have hanging fenders, the fenders are likely to disrupt one another, leaving none in proper position). (SL)
– approaching boat begins by matching pace with the boat that is maintaining its course and speed, beside but still with separation between the two boats (CG)
– when matching speed is achieved, approaching boat maneuvers sideways so as to place forward quarter of approaching boat alongside aft quarter of boat that is maintaining its course and speed (ABS, CG)
– this positioning is for two sailboats (ABS), other positioning may be appropriate for other combinations of boat types (CG, CF)
– depending on the specific situation, consider the possibility of attaching lines to maintain position alongside, as in towing “on the hip,” or consider use of a “sea-painter,” as described in the CG manual on page 377 (section 10-48). (CG, discussion with experienced sailors)
– Both helmspersons should maintain awareness that if transferring person falls overboard, engine(s) should immediately be put in neutral, and steering (motoring or sailing) must be focused on avoiding crushing of crew overboard between vessels, followed by all other standard crew overboard procedures for recovery, to be undertaken after COB is clear of both vessels. (SL)
– when successful transfer is complete, approaching vessel moves away by slightly increasing throttle and gradually steering away from vessel that is maintaining its course and speed (avoiding possible suction at stern of the vessel maintaining its course and speed). (CG)


(ABS) Annapolis Book of Seamanship, fourth edition, by John Rousmaniere. See photo and caption in section on running aground, p 344.

(AU) “Code of Conduct for Carrying out Passenger Transfers between Water Taxis and Other Commercial Vessels Which Are Underway” Waterways Authority – Australian government publication. (retrieved January 19, 2014)

(CF) forum series includes discussions of rafting, use of fender boards while rafting/coming alongside, coming alongside underway, and video of crew transfer between cruising sailboat and container ship. (retrieved January 20, 2014)

(CG) US Coast Guard “Boat Crew Seamanship Manual,” section 10-45 to 10-49, pp 374-378, “Maneuvering Alongside Another Vessel” (retrieved January 19, 2014)

(WC) Wind Check magazine article on crew transfer that was considered between sailboats during 2012 Newport-Bermuda race (retrieved January 18, 2014)

(SL) Shemaya Laurel – this author is NOT an authority on proper boating practice. Background includes recreational safe boating certificates (State of Connecticut, and Boat US), substantial home study, and time on the water. I do not have a USCG captains license (though I would have trained and applied for one if I thought I could pass the required medical exam, and have done some study of captains license educational materials). All critical points in this article come from the above-named sources; the details referenced to me are based upon my limited experience of crew transfer underway.

This article is in no way meant to encourage underway crew transfer – I felt that my experience with it was hazardous, even though it was carried out successfully and without incident. I might or might not choose to do it again. Either way, I came away from the experience feeling aware of a complete lack of background as far as appropriate procedures for this maneuver. This lack of background was in spite of previous study of quite a number of general boat handling references, and home-study courses and materials, including from The US Power Squadron, Chapmans, and a wide range of sailing videos and texts. It was surprising to me that I did not recall seeing anything about this maneuver discussed, and I came away from the above-mentioned crew transfer experience with an interest in filling that gap in my knowledge. This search for information has resulted in the reference list, as well as the compiled procedural notes, that are contained in this blog post. Since it has been such a project to put together, it has seemed to make sense to share this material. However, I want to reiterate that what I have written is not “authoritative,” and is in no way meant to encourage people to try this maneuver! Please include this paragraph, if you copy this post!

It is my hope that people with qualifications much more substantial than mine will begin to include “underway crew transfer between sailboats and other vessels” in their writings about seamanship and boat handling. Either to say “don’t do it,” and why, or to explain procedures with the same kind of detail as that provided by the US Coast Guard and the Australian government in the references listed above.

If readers have come across other underway crew transfer references that I’ve missed, if you would be so kind as to include them in a comment, I would appreciate it very much.


Highline ship to ship crew transfer (just because it’s so interesting!)