Is there any cost to surfing a boat's wake (to the boat in front)

There is one cost. Don't get too close to the ship you are using to wake surf. Several people have been killed by being sucked into the ship by it's wake.

 

Be careful whose wake you surf. Someone once told me they liked military ship wakes - the big ones create a pretty big wake. But in recent years, if you get too close to a military vessel, they will likely assume it is an attack and fire at you. Because even a typical sea kayak, let alone something bigger, could carry enough explosives to do some damage.

Maybe the ferry operator was worried about a similar potential threat?

Plus, if you miscalculate, you could get run over. No safe large boat operator wants to put other people in danger. It is common for them to be trained to try to keep some distance from other boats, especially if they have poor maneuverability.

So, from a safety perspective, I think a ferry operator might be reasonably justified in wanting you to stay clear. But maybe some people here disagree?

 

I second that. And you might get a not so nice visit from the local boating authorities.

 

I admit I don't fully understand entirely the rules of right of way at sea (and what is more, they are sometimes locally amended), but these might be somewhat relevant. In particular, the barge might be required to act to avoid you, to try to prevent collision. And so perhaps are you. So, it is possible that you are either placing the barge in a position where they are trying to follow maritime law, and you are making it difficult to do so, or where you are failing to follow maritime law.

You aren't necessarily alone in trying to do things that might violate maritime convention and law. For example, PWCs often deliberately move back and forth across another boat's wakes. It is possible they can repeatedly cross another boat's stern wake without violating those rules (though there are often specific rules about how close they can come), but bow wakes are another matter.

I have seen a kayaker ask permission of a power boater to ride his wake. It was given. But I am guessing you are not seeking to ask permission, but are acting in a potentially unsafe manner, possibly in violation of the rules of right of way, without warning.

The rules of right of way were specifically intended to make collisions less probable. They are not designed to save energy, or maximize fun. So it may be that they might not be well optimized for your purpose. Because you are trying to do something out of the ordinary, it might benefit you to study these rules and try to figure out how they apply to your situation. For example, you might try to figure out which of you is the "overtaking vessel", and whether the barge might be considered to have a limited ability to maneuver (it probably does), and how that affects your specific situation, according to the rules that apply at your chosen location. And you might try to determine whether there are minimum distance restrictions at that location.

 

Nope, not around here. I know over a dozen local officers with BC Ferries and they'd have no problem with a small boat riding their wake at a safe distance which is easy to do because the old girls wake was so large. If anything, they'd be concerned to see me fall behind when I was forced to stop and refuel. It was a huge safety benefit to me to have such a capable asset nearby. Most of our rescues here are by "vessels of opportunity". It was an uneventful transit, just the way I like 'em.
We used to pace right up against another local ferry while training in the Canadian Coast Guard Zodiac, with permission form it's Captain of course.

 

Fallacy! The rear one is travelling in the propwash of the front one=contrary current

 

drafting bikes is another matter altogether:
the front one does not propell himself by "kicking back" the medium they travel through (air). The ship does
A little thought experiment will show the benefit to the leader by the drafter:
take a streamlined body
half it at mid length & separate front & rear pieces:
front will have more resitance than before,no?
follows: if rear piece travels close to front piece, resistance of front piece lowers.
same with 2 cyclists. The front one gets rid of all the eddies straight behind him, & the rear one of course of much of the wind resistance in his face/front

 

Ummmm...there is a lot more to untangle than that. The "wake" of a powered vessel is composed of 3 parts. The pressure disturbance (i.e. the pressure drag > surface wake waves, longitudinal and transverse), the velocity disturbance (i.e. skin friction > water mass movement in the direction of travel), and the propulsive disturbance (a combined pressure and velocity disturbance that varies with the propulsion method). And the energy expended in the first two is exactly matched by the energy input by the last one.

In the "far field" analysis, there is no overall energy change in the fluid and no effect on the following ship. In the "near field" analysis however, generally, the following vessel benefits by the lowering of the pressure disturbance. This is effectively how bulbous bows work. As far as the skin friction works?...that is a geometry issue tied to the pressure disturbance phasing of the lead vessel and its propulsor. In many cases there is very little "global" prop wash velocity seen by the following vessel. The reason a person standing on the transom seems to perceive an "aftward" prop wash velocity is the rest of the wake is globally moving "forward" with the vessel.