BEAM SEA - friend or foe to deep v planing hull?

I have always steered clear of beam seas - ie seas coming directly at the sides of my boat - ie coming at right angles to my boat.

I have always had the feeling that the best bet is for the pointy end to pierce the waves, however of course experience shows that having a following sea within reason is a great ride.

I have had 2 books lying around for years that I have finally read that say opposite things about beam seas. In "Getting Started in Powerboating" by Bob Armstrong (published in about 95 - excellent book with great techniques for docking and special anchoring with dual anchors etc) he says at page 175 "As much as possible, avoid taking the seas either directly on the bow or against the transom. Avoid beam seas no matter what".

He talks about taking seas front and rear on a slight angle for ride comfort - and my experience is that in choppy head seas in particular an agle of 10-15 degrees make the ride smoother than straight on. Clearly however he is not a fan of beam seas.

In another excellent book "Fast Powerboat Seamanship" by Dag Pyke (published in about 2004) he says in part at 169 "With wind and waves on the beam the ride for a fast boat will be a lot easier than trying to cope with head seas. In beam seas, with wind and waves coming at one side of the boat, there are none of the sudden changes in wave gradient that face the driver in head seas. The ride will be a lot smoother, but you still have to be aware of sudden changes in waves conditions...breaking crests can be a danger in beam seas and these can rear up suddenly alongside the boat. Also with wind on the beam, there is an increased risk that the boat will land on the flat of one side of the hull rather than centrally on the V. In slight and moderate sea conditions, there should be no problem in operating at full throttle in beam seas."

I have seen plenty of boats operate beam on just out from breakers on the gold coast - ie running parrallel to land - but those waves are moderate and a fair way between them - ie not standing up. I have operated on the plane with some amount of swell from the side - but only very slight and the ride is good, but never in the steep sharp chop of moreton when its windy. I guess it depends on the conditions. These 2 authors do seem to be well at odds on this issue however with one saying avoid at all times and the other saying drive in it up to moderate sea conditions...

..what do you think.

Cheers

In the real world many don’t have a choice as to what sea they will drive in. I mean if you were heading out to the Barwon Banks then in every chance you will encounter a sea coming in from the SE. This means the sea is going to be hitting you from the Starboard bow if you’re on a heading of between 100 and 150 degrees. As you know the sea can change in minutes, so picking the sea to drive in is a bit impossible if you ask me. I have worked on boats for more than 20 years and I have experienced some of the worst seas you can imagine. At the end of the day its how you drive the boat and manipulate the trim to the best of your advantage.

Driving to the conditions no matter what style of hull you’re in will always be the best solution to getting home safely. Beam seas aren’t all that dangerous unless they crashing over the gunnels, in which case steering in any direction is going to be dangerous, best not put yourself in that position to begin with. I have had water lapping the gunnels rubber in cats fully loaded with fish and two deck hands, 400ltrs of fuel on board. It could have been the last I ever seen the land again if we didn’t drive to the conditions and balance the boat out on the deck in terms of weight distribution. Every one you ask will have differing opinions no matter what you say. Experience is the best method of learning, just don’t push things to far or you may become shark shit.

Stu

Ozscott for me it's all about scale, when the sea is too large for the ride I am in then a beam sea is to avoided although up until that point I will chase them down and ride comfortably in whatever planing hull I am in.

Great fun if inclined when a few degree course correction is needed (usually because of a lump or pothole of water dead ahead), soft landings on the back or face of the nearby wave and I dont mean rpm limiter sized jumps either just cooshy 1/2 - 2/3 of the hull landings.

cheers fnq

Another thing I found when boating in a trailing sea with tiller steer. If i stuck a bit more weight towards the back of the boat(I.e get your 100kg mate to sit up the back with you and have a really light nose). The ride seems alot safer.. as when you come down infront or behind a wave the nose doesn't dig in and veer offline as much, you can go a few extra knots quite safely...

But I always try and hit the chop at a slight angle for a softer ride, but 90% of the you have no say in what direction the waves come in comparison to where you need to go.

Great advice from Stu IMO, drive to the conditions, be aware of weight distribution and don't push your luck!
For me it's a no-brainer, I'm fortunate to only be out there to enjoy myself.
Slamming about in rough seas, I can live without!
When caught out by the conditions, I find by just being patient and not pushing the limits of the boat, things work out fine.
Cheers.

Most of the time in the Bay if it gets rough i do my best to tack about so that the sea is not on my beam - might be a psychological thing!

Cheers

Ozscot, depends on the height and esp the period, MB seas can be uncomfortable to run along.

cheers fnq

yep - your not wrong about that mate. There are some really ordinary patches coming into Cleveland Pt and Raby Bay - pressure waves back from the shore and higher wind speed near the shore, current and shallow water conspires to make it like a cauldron sometimes with waves coming from every direction - steep also.

Regarding the title of this thread, and one of the book quotes, I would tend to agree that a beam sea in a small deep V planning hull may not be so friendly.
Depending on wave height and period of encounter, and personal experience of a 23 deg hull wanting to lean into the wind, there is the chance of shipping water over the windward gunnel.
If you are carrying a fair load, the boat is leaning into the wind, the seas are short and steep, you can come off the top of a wave land on 1 side of the V in the trough. If this happens you'll find the gunnel top very close to the sea surface, and possibly dipping under. In this scenario, it would be best to try and zig-zag and take the waves on the quarter and the bow.

Its interesting - the book that favours beam seas is written by an ocean racer - he talks about staying ahead of following seas and that the tatic of wave jumping in following seas only works in the bigger seas when doing at least 40 knots and preferrably 50 or so!!. His book does have pictures of smaller and less powerful craft and he notes that smaller deep Vs have to slow down in big seas sooner than big ones but never says what a big one is - I reckon my 21foot vagabond is a small deep V in his terminology (certainly in moreton bay sometimes it feels small, 21 degree stem to stern deadrise and heaps of glass notwithstanding!!!).

Cheers

Ocean racing boats don't have the open deck space our well-deck fishing craft have. They have mostly flush decks and a small cockpit and water on deck isn't as much of a concern. It's no real comparison to the type of boats we use, their length and breadth ratio is vastly different to the common boat used for family or fishing.
Drive to the conditions, possess a good understanding your's and the boat's limitations, and you will have a safe and comfortable passage.
Well, something like that anyway.

regards