November 26, 2007
Rough Water Driving
When driving in rough water, the most important thing to do is to match your speed and direction to the water conditions through adjusting your throttle and steering accordingly. Though it may be a blast to keep the throttle on and wave jump, eventually you and the boat will get tired of it. Just as important however, if the prop is continuously leaving and re-entering the water the efficiency of the boat to make quick headway is greatly reduced.
There are several conditions that operators need to know how to handle. The first is driving upwind to weather or in a "Head Sea".
To do this it's important to first be sure your trim is adjusted all the way down in order to keep the bow down. This will minimize the amount of lift off the wave but also promote the best entry through the water which promotes optimal performance of the V hull to cut through the water.
Long Wavelengths
Now, if you're driving in very large waves with some distance between them (distance between waves = wavelength) I've outlined some helpful tips. Once your trim is adjusted, you want to approach each wave so that you are driving up the face of it carefully easing off on the throttle as you approach to the top so as to not launch off the crest or top. Then, drive down the wave speeding up so that the bow will raise as the next wave approaches.
As you do this, you'll find the ride to be pretty fast and amazingly smooth. Driving into a head sea is actually all about throttling ON and OFF as you make your way through the waves.
Short Wavelengths
With shorter wavelengths or short sharper chop the above method can prove almost impossible to accomplish so try using what I call the "Sailing Method" where you literally "Tack" upwind by driving the RIB at 30º to 45º to the waves. What this does is increase the perceived wavelength which allows the operator to adjust the throttle as described above. Though this will add distance to your trip the improved comfort and safety will be well worth it.
Posted by ribcraftusa at November 26, 2007 10:49 AM
Comments
Yesterday I needed to get a favorite windsurfing spot in my 585. Winds were a solid 25 knots and gusts to 40. Seas were 6 feet plus. Needing to head up wind I tried the advice for short wavelengths and tacked up. It worked great. All of us remained sitting and had a nice conversation. No jarring and surprising dry. Of course it didn't hurt having the deep vee and high bow rise. That's one thing about the design of a Ribcraft, they are great at all points of sail.
Posted by: Dave at December 10, 2007 11:18 AM
Dave - I'm glad the handling advice was helpful. Thanks for reading and giving us an update!
Posted by: Fred at December 12, 2007 05:50 PM
Unfortunateley not many Rib owners know about the hazards of waves. Especially the waves created by large vessels or cruiseliners. We regulary use those waves to "upgrade" a charter with clients. They are steep and high and have an enourmous fun-impact. But unexperienced Rib drivers right next to me also sailing with clients forgot to throttle off and went nose under with 3 people ending in the water.
Your explanation above might help to support those, who think that a Rib can do anything.
Posted by: stephan Rib at January 19, 2008 12:22 PM
Unfortunateley not many Rib owners know about the hazards of waves. Especially the waves created by large vessels or cruiseliners. We regulary use those waves to "upgrade" a charter with clients. They are steep and high and have an enourmous fun-impact. But unexperienced Rib drivers right next to me also sailing with clients forgot to throttle off and went nose under with 3 people ending in the water.
Your explanation above might help to support those, who think that a Rib can do anything.
Posted by: stephan Rib at January 19, 2008 12:23 PM
It is very true what you guys commented here, I am used to drive in very rough waters of the atlantic with sea states up to state 5 with a beaufort scale of 6-7 with winds in excess of 30 knots sometimes, one thing that is very important in rough conditions is to plan the mission and execute it well, you and your crew must be well trained and prepared for any situations at sea. With regard to the coxswaining - the coxswain must know the limits of his boat, he must stick to his rehearsed navigation plan and he must read the sea well. The coxswain and commander/navigator must talk constantly to ensure good communication and the coxswain must trim the propellers according to the direction he is steering, when he has headsea and spray he must trim in the engines accordingly to prevent the boat getting airborne and not to loose momentum and when he has following sea he must trim out accordingly to avoid scoffing. I have more than 12 years experience with high speed rigid boats, pencil boats and RHIBS along the South Arican coastline and I have been to the north sea, you always learn, such a joy to be out there with a good boat, you are welcome to contact me if you have any questions or anything to share, take care.
Posted by: Martin at March 15, 2008 08:10 AM
